Electronic musical instrument

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. Upon completion of the operation of the counter, this modification of the key code is stopped and the key code is restored to the original key code resulting in production of the principal tone. In the foregoing manner, a grace tone preceding the principal tone can be played simply by depressing a single key. The counter is also arranged to start the counting operation upon release of the depressed key with a result that a grace tone following the principal tone can be played. Further, ornamentation called 'trill' can also be produced by alternately and repetitively opening and closing the gate by means of the output of the counter.