Abstract: A chord-playing robot system is disclosed. The robot system includes a computer including an anti-collision program, two linear motors, two moving devices, and two finger-like devices. The finger-like devices are respectively connected with the moving devices. The anti-collision program is executed to prevent the moving devices from colliding with each other. The linear motors are controlled by the computer and are operable to drive the moving devices. Each finger-like device includes a plurality of tubular solenoids and a plurality of electromagnetic bars. The tubular solenoids are disposed in alternating sequence in two rows. The computer is operable to determine if there is any one of the tubular solenoids shall be switched on. The at least one tubular solenoid, upon switched on, is configured to move the associated electromagnetic bar toward for pressing a key on a piano.

Abstract: An automatic player piano is broken down into an acoustic piano and an automatic playing system, and solenoid-operated key actuators are driven to rotate the black/white keys of the acoustic piano; the space between the keyboard and the array of black/white keys is so narrow that the manufacturer provides the solenoid-operated key actuators in the space below the key bed; plunger holes are formed in the rear portion of the key bed, and the solenoids occupy the space under the key bed so that the plungers project through the plunger holes into the space beneath the rear portions of the keys; the key bed is does not lose the mechanical strength so that the tuning work is not frequently required for the key action units.

Abstract: A transducer for a musical instrument through which vibrations can be fed back to the instrument so that notes played on the instrument can be sustained. The transducer comprises a bracket for mounting the transducer to the instrument. First and second opposited permanent magnetic poles project away from the bracket. A first surface of a sheet of non-magnetic, non-electromagnetic resilient material is attached to the projecting first and second magnetic poles. An electromagnetic core has a spine and first and second legs originating at, and extending away from, the spine and terminating at first and second end faces, respectively. The first and second end faces are attached to a surface of the sheet opposite the surface of the sheet to which the permanent magnetic poles are attached, with the first face adjacent the first permanent magnetic pole and the second face adjacent the second permanent magnetic pole. A conductor is wound on the core.

Abstract: An electric stringed instrument such as a guitar having a sound reproducing element on the top of the neck for feeding the tones of the strings back into the guitar. (A sound reproducing element being a speaker or an electromagnetic transducer.) The tones of the strings are sent from the pickup to an amplifier and then to the sound reproducing element. This feedback will either prolong the note played or one of its harmonics or will not have any effect depending upon which note is played. Two wires are imbedded in the back of the neck to bring the electric signal to the sound reproducing element.

Abstract: A musical instrument with a plurality of vibratile tone generators, whose oscillations are converted into alternating currents by electroacoustic transducers, is provided with a control circuit feeding back a regenerative vibratory signal of progressively diminishing amplitude to maintain the oscillations of a previously activated tone generator for a selected fade-out period. The duration of the fade-out period can be controlled by the player, e.g. with the aid of a pedal, by varying the time constant of a peak-storage network connected to the feedback loop. The feedback signal may be transmitted to the respective tone generator by a mechanical vibrator attached to the instrument body or by sound waves emitted from a loudspeaker. The player may also switch from the output of the peak-storage network to a constant control signal for sustained reverberation.

Abstract: A stringed instrument with feedback is formed from a string of 30 to 100 feet in length stretched taught and having pickup and driving transducers located at respective opposite ends of the string. An electronic processing system receives a signal from the pickup transducer and feeds it to the driving transducer. Each transducer comprises a pair of transducers oriented at right angles to each other and to the string, thus allowing for two independent signal channels to exist in the system.

Abstract: The guitar has a novel feedback arrangement for sustaining the sound generated from the strings and including a pickup associated with each string and a corresponding driver intercoupled with the pickup in a feedback loop that also includes a gain-controlled amplifier. The amplifiers are controlled in common from a variable control means. The pickups, drivers and associated electronics are all commonly mounted from the bridge. In an alternate embodiment of the invention there is provided an improved sustain technique that provides a more natural sustain characteristic, employing a parametric type of excitation. This embodiment may comprise a pickup, amplifier and tensioning member responsive to the output of the amplifier for sustaining string vibration by causing longitudinal string displacement by means of the tensioning member. In a similar embodiment the string tension may be held constant and the string length varied instead.

Abstract: .Iadd.In a method and apparatus for controlling musical sounds there is provided a housing with an inner cavity and a mouthpiece forming an air channel and a loudspeaker cone for vibrating the air in the inner cavity for introducing sound energy into the oral cavity of a player via the mouthpiece. The sound energy is acoustically monitored by a microphone which produces an output control signal that is used to control the pitch of an electric sound generator in relation to the size of the oral cavity. .Iaddend. Means forming an air channel is connected between the output of .[.a.]. .Iadd.the .Iaddend.loudspeaker and the input of .[.a.]. .Iadd.the .Iaddend.microphone. The output of the microphone is amplified by means of an amplifier, the output of the amplifier being fed to the speaker, an acoustical feedback path thus being formed between the speaker and the microphone.