Abstract: In an automatic accompaniment apparatus for electronic musical instrument capable of automatically generating accompaniment tones such as base tones, chord tones and arpeggio tones, arrangement is provided so that, at each time of depressing keys on an accompaniment keyboard, accompaniment key data for accompaniment tones which may possibly be sounded, are previously formed and secured, and the selected ones of the key data for the selected accompaniment are outputted at accompaniment tone generating timings synchronous with the rhythm. Thus bass tone, chord tones, arpeggio tones etc. may be generated in sufficient synchronous relation with a selected rhythm even by adopting a time-divisional processing using a low-speed compact computer such as a micro-computer.

Abstract: A three-keyboard electronic musical instrument of the type generating binary-coded primary key data representative of notes played on the keyboards, and secondary key data representative of unplayed notes that are correlated with the played notes in some musically favorable way. Prior to introduction into a multi-channel tone generator circuit, part of the primary key data and all of the secondary key data are directed into a key data memory having storage channels corresponding in number to the sounding channels in the tone generator circuit available for such data. A discrimination data memory has a plurality of storage locations, corresponding to the storage channels of the key data memory, for storing binary-coded data representing the discrimination between the primary and the secondary key data stored on the corresponding storage channels of the key data memory.

Abstract: A polyphonic, keyboard-type electronic musical instrument capable of automatic production, in response to key depressions on upper and lower keyboards, of "fill notes" which bear the same note names as the depressed lower keys but which, preferably, fall within an octave below the lowest pressed upper key at every moment. The instrument is of the type wherein each depressed key is coded into key data in accordance with a binary "key code" composed of a note code and an octave code. The note code identifies the note name of each key, whereas the octave code identifies the octave to which the key belongs. Upon depression of a key on each of the upper and lower keyboards, the note-coded data derived from the key date representative of the depressed lower key are combined with the octave-coded data derived from the key data representative of the depressed upper key if the note name of the depressed lower key is below that of the depressed upper key.

Abstract: An electronic musical instrument is of a type wherein musical tone waveforms are stored in a memory as their sampled amplitudes and sequentially and repetitively read out to constitute tone waveforms. A key depression brings forth key code in a digital representation. This key code is used for reading out frequency information from a frequency information memory. The frequency information is accumulated to make an address signal for reading out the waveform memory.When a key is depressed, a counter starts counting and opens a gate for a predetermined period of time. The gate passes a code representative of an interval of a grace note with respect to the note of the depressed key (i.e. principal note) to an addition and subtraction circuit for addition or subtraction between the key code and the code representative of the interval for the grace note. Accordingly, the key code is modified and the desired grace tone is produced.

Abstract: An electronic musical instrument is of a type wherein musical tone waveforms are stored in a memory as their sampled amplitudes and sequentially and repetitively read out to constitute tone waveforms. A key depression brings forth key code in a digital representation. This key code is used for reading out frequency information from a frequency information memory. The frequency informaton is accumulated to make an address signal for reading out the waveform memory. The read out waveform is reproduced as a musical tone through a tone-color and volume control circuit. This tone-color and volume control circuit is controlled keyboard by keyboard.The key code produced upon depression of the key contains a signal representing the kind of the keyboard to which the depressed key belongs. This signal is applied to a conversion circuit and converted to a signal representative of a different kind of keyboard.

Abstract: An electronic musical instrument is of a type wherein musical tone waveforms are stored in a memory as their sampled amplitudes and sequentially and repetitively read out to constitute tone waveforms. A key depression brings forth frequency information in a digital representation. The frequency information is accumulated to make an address signal for reading out the waveform memory. When a depressed key is moved laterally, a touch detection circuit produces an analog detection signal representing the amount of displacement of the key. In the meanwhile, a clock pulse is counted by an up-down counter and the counting output is converted by a D-A converter to an analog signal to obtain a triangular wave function signal. When the analog detection signal coincides, in amplitude, with the triangular wave function signal, the digital signal from the up-down counter is sampled and held by a sample and hold circuit. Thus a digital signal representing the key displacement is obtained.

Abstract: An electronic musical instrument is of a type wherein an envelope to be imparted to a musical tone is stored in a memory as its sampled values and sequentially read out to constitute an envelope shape. A key depression causes the read-out of the memory.The instrument is improved to provide a rich sound effect of legato performance by successively and smoothly shifting the tone of the former key to that of the latter key while maintaining a predetermined constant tone volume. This legato effect can be carried out by successively maintaining the sustain level of the musical tone envelope from the tone of the former key shifted to the latter key. The musical tone envelope is read from the envelope memory by an address which is shifted by a clock pulse.

Abstract: An electronic musical instrument of a type wherein a plurality of systems are provided each system comprising memories storing respective harmonic component waveshapes which are read at the same reading rate and the read out harmonic waveshapes are suitably mixed to obtain a desired musical tone. Each system also comprises a circuit for controlling the envelope of the waveshapes read from the memories. In the first system, the envelope control is made in such a manner that the envelope will rise upon depression of a key, thereafter maintain a constant level as long as the key is kept depressed and decay upon release of the depressed key. In the second system, the envelope is controlled so that the envelope will rise in a short time and immediately decay thereafter. The respective harmonic waveshapes thus controlled in envelope in the respective systems are then suitably selected and mixed together.