Abstract: A key assembly includes a capstan and a key. The key includes an upper surface, a hole part having a first inner side surface supporting the capstan, and an opening part arranged between the upper surface and the hole part, the opening part having a second inner side surface surrounding the capstan.

Abstract: A keyboard apparatus includes: a key; a frame; and a connecting portion configured to connect the key and the frame to each other. The connecting portion includes a flexible member having a rod shape and having flexibility that enables the key to pivot with respect to the frame. The flexible member includes a portion that, in entirety of a range of pivotal movement of the key, maintains a state in which a length of a line extending along a neutral axis of the flexible member between two points located on the neutral axis is greater than a length of a straight line connecting the two points to each other.

Abstract: A split keyboard with an optional middle section of keys for controlling regular PC input to a host, to play music, and to input and play music with a multiple octave keyboard that when the middle section of keys are removed can be portable to travel. And when working on just the split keyboard inputting data to a host the operator arms are not abducted due to the perpendicular advantage or slide apart keyboard where an operators arms are perpendicular to the keyboard keys.

Abstract: A key switch for an electronic piano, which makes it possible to increase an allowable range for shift of a movable contact without increasing the size of the key switch of the three-contact type. The key switch includes a substrate having first to third stationary contacts arranged thereon side by side in the lengthwise direction of a pivotal member as one of a key and a hammer. Each stationary contact has a common contact and a non-common contact. The common contact has an extended portion extending between two non-common contacts. The key switch has first to third movable contacts arranged side by side on an elastic switch body, for being sequentially brought into contact with the common contacts and non-common contacts of the stationary contacts as the switch body is pressed by the pivotal member, to thereby output signals indicative of key depression information.

Abstract: A key press switch includes a main body portion configured to contact a pseudo hammer of the electronic piano and a contact portion provided in a part of the main body portion to contact the pseudo hammer. The contact portion includes a first contact portion and a second contact portion located closer to the fulcrum than the first contact portion. The contact portion is configured such that a contact position with the pseudo hammer is shifted from the first contact portion to the second contact portion in accordance with the key press amount of the electronic piano from the amount at which, in a standard acoustic piano, the damper load starts to be applied until the amount at which, in a standard acoustic piano, the damper load has been fully applied.

Abstract: A key press switch includes a main body portion configured to contact a pseudo hammer of the electronic piano and a contact portion provided in a part of the main body portion to contact the pseudo hammer. The contact portion includes a first contact portion and a second contact portion located closer to the fulcrum than the first contact portion. The contact portion is configured such that a contact position with the pseudo hammer is shifted from the first contact portion to the second contact portion in accordance with the key press amount of the electronic piano from the amount at which, in a standard acoustic piano, the damper load starts to be applied until the amount at which, in a standard acoustic piano, the damper load has been fully applied.

Abstract: A keyboard device for an electronic keyboard instrument, including several keys arranged side by side in a left-right direction, a hammer support disposed rearward of the keys, a plurality of hammers pivotally supported by the hammer support to be pivotally moved in accordance with key depression, and a key switch having a plurality of switch bodies provided in association with the respective hammers and a switch board mounted to the hammer support. The hammer support has a hammer supporting part for supporting the hammers and a switch mounting part to which the key switch is mounted, and is formed by an injection molded article of a predetermined kind of synthetic resin.

Abstract: A key switch for an electronic piano, which makes it possible to increase an allowable range for shift of a movable contact without increasing the size of the key switch of the three-contact type. The key switch includes a substrate having first to third stationary contacts arranged thereon side by side in the lengthwise direction of a pivotal member as one of a key and a hammer. Each stationary contact has a common contact and a non-common contact. The common contact has an extended portion extending between two non-common contacts. The key switch has first to third movable contacts arranged side by side on an elastic switch body, for being sequentially brought into contact with the common contacts and non-common contacts of the stationary contacts as the switch body is pressed by the pivotal member, to thereby output signals indicative of key depression information.

Abstract: An electronic keyboard instrument with a hammer action, in which a circuit board for generating electronic musical tones can be disposed at a location for easy maintenance and for effective space utilization. Front and rear bars are bridged between side plates of an instrument main body so as to extend parallel to each other in the left-right direction and reinforce the instrument main body. A hammer action mechanism having hammers for respective keys is disposed rearward of a key-depression part of a keyboard and upward of a rear end portion of the keyboard, and a board tray is bridged between the front and rear bars. The board tray and the circuit board are located upward of the hammer action mechanism.

Abstract: An electronic fingerboard for use on a musical instrument comprises a printed circuit board layer with contact electrodes and electronic sensing components. A first double sided adhesive tape is formed over the printed circuit board layer, and a polyester film membrane having carbon printing on the lower surface thereof is formed above the first double sided adhesive tape. A second double sided adhesive tape is formed above the polyester film membrane, and a silicon rubber overlay is mounted over the second double sided adhesive layer. A polyurethane overspray comprising a non-stick coating is then formed on the silicon rubber overlay.

Abstract: Plural key switches are arranged in two dimensions along X- and Y-coordinate axes, and an X-coordinate position of each of the key switches is associated with tone generation timing while a Y-coordinate position of each of the key switches is associated with a tone pitch. Storage section stores a music piece data set that includes tone generating data having data of tone pitches and tone generation timing associated with the key switches. In a repeat-section setting mode, a repeat-section setting section causes the plural key switches to function as setting operators and sets a repeat section of the music piece data set on the basis of the X-coordinate position of any operated one of the key switches. In reproduction of the stored music piece data set, a reproduction section repetitively reproduces the tone generating data of the music piece data set which are included in the set repeat section.

Abstract: A media application for providing outputs (e.g., audio outputs) in response to inputs received from an input device is provided. The media application may connect input mechanisms of an input device with parameters of channel strips (e.g., which may define output sounds) using an intermediate screen object. The media application may first assign an input mechanism to a screen object, and separately map a screen object to a channel strip parameter. The media application may map a screen object to several channel strips simultaneously such that, based on the value of the screen object, the volume of each of the several channel strips changes. The media application may provide a graphical representation of available channel strips using layers. As the media application accesses a channel strip, the appearance of the portion of the layer associated with the channel strip may change.

Abstract: There is provided a touch detecting device of a keyboard instrument, which makes it possible not only to enhance the mounting density of a plurality of optical sensors, but also to detect touch information of a key with high accuracy without being affected by light from the other optical sensors.

Abstract: An electronic keyboard instrument which is capable of easily carrying out an arpeggio performance rich in variety by a simple operation on a touch strip. The electronic keyboard instrument has a belt-like touch strip on which a player slides his finger while touching it to carry out an arpeggio performance. A CPU causes musical tones of respective pitch names included in respective designated component pitch names to be sounded, in a predetermined arpeggio pattern having a predetermined sounding order, according to detected touch positions on the touch strip, for the arpeggio performance. A musical tone generating circuit for generating musical tones for the arpeggio performance is switched between first and second tone generator circuits for generating musical tones based on key-on information detected on swingable keys and a third tone generator circuit dedicated to generation of musical tones for the arpeggio performance.

Abstract: An electronic keyboard that includes a plurality of keys including a first key. The keyboard further includes a key support supporting the first key for movement between a rest position and a depressed position. The keyboard also includes a first key return spring configured to apply a return force to the first key to bias the first key toward the rest position. In the keyboard, the first key return spring is configured such that the return force has a substantially constant magnitude throughout the movement of the first key between the rest position and the depressed position.

Abstract: Plural key switches are arranged in two dimensions along X- and Y-coordinate axes, and an X-coordinate position of each of the key switches is associated with tone generation timing while a Y-coordinate position of each of the key switches is associated with a tone pitch. Storage section stores a music piece data set that includes tone generating data having data of tone pitches and tone generation timing associated with the key switches. In a repeat-section setting mode, a repeat-section setting section causes the plural key switches to function as setting operators and sets a repeat section of the music piece data set on the basis of the X-coordinate position of any operated one of the key switches. In reproduction of the stored music piece data set, a reproduction section repetitively reproduces the tone generating data of the music piece data set which are included in the set repeat section.

Abstract: A supporting system is provided on a saxophone for offering assistance to the player, and includes pressure sensors monitoring the touch pieces of the keys, power assisting units equipped with torque motors provided for the keys and a controller connected to the pressure sensors and the power assisting units; a conversion table for depressed touch pieces and another conversion table for released touch pieces are prepared in the controller, and different relations between the finger force and the amount of current to be supplied to the torque motor are respectively defined in the conversion tables, respectively; the amount of current to be supplied is read out from the conversion tables depending upon the increase and decrease of finger force so that the player quickly closes the tone whole with the padded cup without curious key touch.

Abstract: An electronic keyboard that includes a plurality of keys including a first key. The keyboard further includes a key support supporting the first key for movement between a rest position and a depressed position. The keyboard also includes a first key return spring configured to apply a return force to the first key to bias the first key toward the rest position. In the keyboard, the first key return spring is configured such that the return force has a substantially constant magnitude throughout the movement of the first key between the rest position and the depressed position.

Abstract: An electronic keyboard that includes a plurality of keys including a first key. The keyboard further includes a key support supporting the first key for movement between a rest position and a depressed position. The keyboard also includes a first key return spring configured to apply a return force to the first key to bias the first key toward the rest position. In the keyboard, the first key return spring is configured such that the return force has a substantially constant magnitude throughout the movement of the first key between the rest position and the depressed position.

Abstract: An optical modulator is hung from a key moved on a key trajectory so as to be moved together with the key, and a light beam, which is stationary with respect to a key bed, is radiated through the optical modulator; a large number of miniature refractors are formed on the light output surface of the optical modulator, and the density of miniature refractors per unit area is varied in a direction in which the optical modulator is moved together with the key so that the current key position is converted to the amount of light passing through the optical modulator; since the miniature refractors and other portions of optical modulator have a unitary structure, a molding process is used for the optical modulator, and the molding process make the production cost low.

Abstract: The present invention relates to a percussion assembly comprising a multitude of percussion instruments, means for playing said percussion instruments and input means for inputting a tone pitch selection for the purpose of producing a tone pitch selection signal. The percussion assembly further comprises sensor means for producing a synchronisation signal when at least one of said percussion instruments is being played. The percussion assembly furthermore comprises control means for receiving the tone pitch selection signal and the synchronisation signal and for producing an audio signal dependent on the tone pitch selection signal synchronously with the synchronisation signal. The invention further relates to drumsticks and to input means for use with a percussion assembly as described in the foregoing.

Abstract: A musical instrument amplification system comprising a footswitch and a main amplification device, its control panel having a variety of controls, such as switches, sliders, dials and the like allowing the user to set a variety of parameters for amplification. A remote footswitch having several controls is connected to the front-panel, the controls may be assigned either to a set of specific amplification parameters, or to the control for a particular parameter, allowing the performer improved access to the amplifier controls whilst performing.

Abstract: Disclosed is a modular electronic musical keyboard performance system that can be separated into modules for better portability and flexibility.

Abstract: There is provided a touch detecting device of a keyboard instrument, which makes it possible not only to enhance the mounting density of a plurality of optical sensors, but also to detect touch information of a key with high accuracy without being affected by light from the other optical sensors.

Abstract: An electronic percussion instrument includes input means and musical tone generation control means. The input means allows for a vibration level of a vibration of an operator and position information that conforms to a position of the operator to be input. The musical tone generation control means in one in which whether or not the generation of a musical tone based on the vibration level and the position information is instructed is controlled in those cases where the vibration level has been input by the input means.

Abstract: A method and system for controlling actuators in a mechanical reproducing piano or other instrument. In one implementation, a single finite state machine is provided to control all the actuators. The finite state machine may be or include a shift register or a toggle register, which increases the operating speed. When a note is to be played, the desired dynamic is mapped into a start vector and a stop vector. The actuator is turned on when the state of the finite state machine is equal to the start vector, and is turned off when the state of the finite state machine is equal to the stop vector. Furthermore, the period of the finite state machine is adjusted to be directly proportional to the supply voltage. This allows notes to be played at the desired dynamics even when the supply voltage fluctuates.

Abstract: A keyboard (25) has keys (10) mounted to pivot about a vertical axis as well as about a horizontal axis. Movement of the keys (10) about tile vertical axis is detected to adjust the sounds provided by the musical instrument resulting from striking the keys (10). Wells may be provided with a substance that is selectively solid and fluid. An electronic string instrument emulator has an electromagnetic string and a bow with ferromagnetic material. A method for performing musical instruments includes adjusting the temperament of the instrument during performance based on the music being played. A keyboard instrument may be caused to sound using suitably arrayed electromagnets.

Abstract: A hybrid keyboard musical instrument is fabricated on a piano, and a hammer stopper and an electronic tone generating system are installed in the piano; the electronic tone generating system includes hammer sensors arranged on a framework secured to a shank flange rail by means of stud bolts, and the stud bolts and spacer nuts, which are threaded with the stud bolts, serve as locators for locating the sensors at target relative positions with respect to the hammers independently in the fore-and-aft direction and up-and-down direction; the framework is pressed to the spacer nuts with nuts driven into the stud bolts so that the framework is removable from and reassembled with the shank flange rail without loosening the stud bolts.

Abstract: A method of controlling music playback includes providing a sensor array comprising first sensors arranged adjacent to one another, receiving data output from first sensors of the sensor array, the data including activation times during which each of the first sensors was activated, comparing the activation times of each first sensor to determine if the first sensors were sequentially activated along a first direction or a second direction opposite to the first direction, controlling the music to be played in a forward direction if the first sensors were sequentially activated along the first direction, and controlling the music to be played in a backward direction if the first sensors were sequentially activated along the second direction.

Abstract: Embodiments of an electronic, frameless, musical keyboard with the ability to couple to other frameless musical keyboards are described. In one embodiment, a first musical keyboard section includes an arrangement of black and white keys, similar to a layout of a piano keyboard, disposed over a base. The keys at the left and/or right sides of the keyboard section have exposed sides, so that a second keyboard section can be integrated with the first keyboard section to give the appearance of a single keyboard. To integrate the first keyboard section with the second keyboard section, the base of the first keyboard section extends past the right-most key to a width and length that is substantially equal to the dimensions of a left-most key from the second keyboard section. The left-most key can then be laid to rest over the extended base portion. The reserved space formed by the base of the first keyboard section having dimensions of a key (e.g.

Abstract: An invention extending functionality and applications of traditional music keyboards. Individual musical keyboard keys may have individual key displacement sensors measuring key travel. Individual keys may further include surface sensors measuring two additional parameters, creating three independent continuous parameters essential for controlled rendering of vowel sounds and orchestral timbre spaces. Surface sensors may comprise pressure sensor arrays, which, via geometric image-processing, may produce five to six readily controlled independent parameters per key, useful in controlling expressive soloing and long-duration background sounds. Per-key pressure sensor arrays may comprise mass-produced modular components including intelligent distributed image processing to simplify manufacturing and substantially reduce cost. Synthesized tactile feedback may render variable keyboard actions or create ‘multi-level’ key travel functionality. Outgoing MIDI signals may also be provided.

Abstract: A Plurality of key switches for tone-generating are arranged two-dimensionally. Mode setting section sets a tone adjusting mode in which the key switches are caused to function as tone-adjusting operators. In the tone adjusting mode, adjustment of a predetermined tone factor (e.g., tone pitch, tone length, tone volume or tone color) is permitted in response to operation of the key switch. For example, once a user moves a finger to change a Y-coordinate position of the key switch in the tone adjusting mode, an amount of the movement, i.e. a difference between Y-coordinates of two or more successively-operated key switches, is detected, and the thus-detected movement amount is set as a value for adjusting a tone volume or the like. All of light-emitting elements located at Y-coordinate positions of the key switches may be illuminated in a line, to allow the user to visually confirm the adjustment and operation.

Abstract: A saxophone has a complicated key mechanism for selectively closing and opening tone holes, and fingering on touch buttons and keys is not easy for children, handicapped persons and old players; a supporting system is combined with the saxophone so as to assist a human player in fingering, and includes sensors, actuators and a controlling unit; while the human player is fingering on the touch buttons and keys, the sensors inform the controlling unit of changes of the depressed touch buttons and depressed keys, and the controlling unit supplies driving signals to the actuators associated with the tone holes to be closed so as to permit the human player easily and quickly to play music tunes.

Abstract: Keys of an acoustic piano require balancers for cancellation of a part of self weight of the action units/hammers; however, the balancers are liable to be dropped off due to the aged deterioration of the wooden bars; in order to keep the balancers stable in the keys against the aged deterioration, the balancer is plastically deformed so as to bite into the wooden bar, the balancer, which is formed with thorns, is rotated so as to make the thorns bite into the wooden bar, the balancer is shaped into a configuration different from the holes so as to exert resilient force on the inner surface in a direction in parallel to the grain of wood, or the balancer is inserted into a constricted hole so as to strongly exert the resilient force on the inner surface, thereby being prevented from the dropping off from the keys.

Abstract: An electronic keyboard that includes a plurality of keys including a first key. The keyboard further includes a key support supporting the first key for movement between a rest position and a depressed position. The keyboard also includes a first key return spring configured to apply a return force to the first key to bias the first key toward the rest position. In the keyboard, the first key return spring is configured such that the return force has a substantially constant magnitude throughout the movement of the first key between the rest position and the depressed position.

Abstract: A key driving apparatus for driving a key may include, but is not limited to, a first elastically deformable unit. The first elastically deformable unit is configured to receive a first control voltage. The first elastically deformable unit is configured to show elastic deformations of stretch and shrinkage based on the level of the first control voltage. The first elastically deformable unit is configured to allow the key to be driven by the elastic deformations of stretch and shrinkage of the first elastically deformable unit.

Abstract: A key operation detection unit of an electronic keyboard instrument that suppresses increase in reaction forces with key depression operation, to improve a key touch feeling. A depression operation of any one of keys of the keyboard instrument is detected by first and second corresponding detectors of the detection unit. The detectors are surrounded by an outer resilient projection and each comprised of an inner resilient projection and a movable portion extending therefrom toward a base plate of the unit. With key depression, the movable portion of the first detector is in contact with the base plate and its inner resilient projection is deformed to generate a reaction force. With further key depression, the inner resilient projection of the second detector brought in contact with the base plate is deformed to generate a reaction force smaller than the reaction force from the first detector.

Abstract: A 2 manual musical keyboard with the pitch progression on one of the manuals reversed. The keys on these manuals are segregated into 2 groups of 2 different heights in the same way as a standard musical keyboard. The key configurations on these manuals have 12 semi-tones linearly distributed across 12 keys of alternating heights. Instead of the traditional 7 lower keys (white) and 5 upper keys (black), this arrangement has 6 lower keys and 6 upper keys. The notation system for this unique keyboard is a dual character set. Six unique characters for the upper keys and six unique characters for the lower keys. The musical staff for this unique keyboard will have six lines assigned to one character set and the six spaces assigned to the other character set.

Abstract: An integrated computer and music keyboard module includes a key assembled base, on a first side of which a plurality of music keys are parallelly arranged. The key assembled base is provided on at least one lateral end with a connecting member for turnably connecting at least one extended module thereto. The extended module includes an extended key assembled base, on a first side of which a plurality of music keys are arranged, and on a second side of which a plurality of computer keys are arranged. When the extended module is turned about the connecting member to an extended position, a music keyboard is shown; and when the extended module is turned to a folded position, the computer keys are exposed to serve as a computer keyboard.

Abstract: An illuminated keyboard with illuminated figures being formed on the top surface of the keyboard including: a top cover, a bottom cover, a plurality of keys and an electroluminescent board. The top cover accommodates the keys and is combined with the bottom cover. The electroluminescent board is installed between the top cover and the bottom cover. The electroluminescent board includes at least one figured pattern to be displayed on a top surface of the keyboard on the top cover when the electroluminescent board is electrified to give light.

Abstract: A keyboard apparatus is provided with a key unit that has a plurality of keys supported for pivotal motion. Also provided is a detection section for detecting a key speed when any of the keys are pivoted. The key unit and detection section are supported by a housing having a bottom member formed of a resin. A reinforcing member having a sufficient rigidity is provided to reinforce the bottom member of the housing such as to reduce warping of the bottom member so as to reduce movement of the detection section as a result of warping of the bottom member.

Abstract: A polyphonic instrument comprises a geometric system coupled with a user interface and a method for generating tone using fluid. The geometric system is arranged such that each point corresponds to a mechanism underlying a malleable surface and is sequentially based upon the 12 tone system of music. The instrument also provides a new method for generating tone by the means of using fluid, whereby a specific frequency is picked up by a separate hydrophone or fluid based transducer submerged in a sealed and removable fluid containment unit having a rotational element also contained within for each note indicated. The rotational element when arranged in a series of graduated units and/or in combination with graduated sub-containment units of fluid changing in scale for separate frequencies, will generate separate tones which may be manipulated through physical and/or analog/digital electronic means.

Abstract: A musical keyboard having associated therewith a alphanumeric keyboard having a plurality of alphanumeric keys, the musical keyboard having a musical keys each being for producing a musical sound, and music function keys for producing musical effects, At least one of the alphanumeric keys is able to be used to modify a result of one or more of the music function keys and musical keys. The music function keys have functionality to produce the musical effect. The modification is only affective while the alphanumeric key is pressed after the musical function key has been pressed. The modification is to change the musical sound produced by the musical keys, and a further modification can be effected by relatively rapid hits of the one key of the plurality of alphanumeric keys. A method is also disclosed.

Abstract: A musical instrument apparatus including multiple parallel strings defining a string line and a keyboard overlay positioned at an acute angle to the string line to allow for consistent playing feel by consistently positioning the hammers on the keys while allowing large key spacing with minimized distance between the strings. The hammers are directly mounted to the keys and are adapted to either cause vibration of the strings or clamp the strings against the upper surface of a neck board so that the strings may have multi tonal capabilities as is commonly used with a fret board neck on a guitar. The strings can be played with just the keyboard, but the strings also extend past an edge of the keyboard overlay so that the user can directly play the multiple parallel strings to achieve a guitar sound. Both an electrical pickup and an acoustical body are provided for further sound variety.

Abstract: An electronic grand piano comprises a plurality of keys arranged on a keybed, a plurality of actions interlocked with the keys, and an electric circuit unit for performing tone-generation operations based on operations of the actions when the keys are operated. A pair of slide portions, each having an elongated shape, are arranged in parallel and are fixed to outer peripheries of the electric circuit unit. A pair of guide portions are arranged in parallel with respect to a main body of the piano and are loosely engaged with the slide portions. When the electric circuit unit is moved in a prescribed direction relative to the main body, it is automatically stopped and fixed at a prescribed position by means of a fixing structure.

Abstract: A keyboard apparatus is provided with a key unit that has a plurality of keys supported for pivotal motion. Also provided is a detection section for detecting a key speed when any of the keys are pivoted. The key unit and detection section are supported by a housing having a bottom member formed of a resin. A reinforcing member having a sufficient rigidity is provided to reinforce the bottom member of the housing such as to reduce warping of the bottom member so as to reduce movement of the detection section as a result of warping of the bottom member.

Abstract: A keyboard and a method for manufacturing the keyboard using silicon rubber. The method for manufacturing the keyboard includes forming sheets from silicon rubber; forming the sheets into a top pad with keys integrally formed thereon and a bottom pad bonded to a bottom surface of the top pad; painting the keys through a silk-screen printing method; and bonding the top and bottom pads with silicon liquid rubber in a state where a flexible printed circuit board is interposed between the pads. The keyboard is configured such that the painted keys are arranged on a top surface of the top pad and the flexible printed circuit board is interposed between the top and bottom pads so that the flexible printed circuit board is electrically contacted to produce a desired sound from a speaker of a controller when a user strikes the keys.

Abstract: A key depression detection apparatus is constituted by a sensor case incorporating key sensors, which can be easily adjusted in positions relative to an arrangement of keys on a keyboard frame (or a keybed) in a keyboard instrument such as a piano. The sensor case has a case body incorporating a key sensor and is affixed to a base member that is fixed to the keyboard frame by using a fixing member, which is constituted by a lower member and a pair of upper members. The legs of the case body are securely held by the fixing member between the lower member and upper members, which are connected together using screws accompanied with springs. Thus, an operator can easily adjust the sensor case in position relative to an arrangement of keys by manually controlling screws.

Abstract: An optical sensor array includes plural sensor heads arranged on a supporting plate at intervals for monitoring moving objects such as black/white keys of a composite keyboard musical instrument; the sensor head has resiliently deformable arms on both side portions thereof and a locating hole/guide groove are formed in the reverse surface portion of the sensor head, and an expander, a grip and projections are formed in the supporting plate; when a worker slides the sensor head on the expander, the resiliently deformable arms make the gap wider so that the grip is pinched between the resiliently deformable arms and that the projections are engaged with the locating hole and guide groove, whereby the sensor head is easily fixed to and located at a predetermined position on the supporting plate.

Abstract: An electronic grand piano comprises a plurality of keys arranged on a keybed, a plurality of actions interlocked with the keys, and an electric circuit unit for performing tone-generation operations based on operations of the actions when the keys are operated. A pair of slide portions, each having an elongated shape, are arranged in parallel and are fixed to outer peripheries of the electric circuit unit. A pair of guide portions are arranged in parallel with respect to a main body of the piano and are loosely engaged with the slide portions. When the electric circuit unit is moved in a prescribed direction relative to the main body, it is automatically stopped and fixed at a prescribed position by means of a fixing structure.