Electronic musical instrument capable of producing ’’chord pyramid’’ arpeggio effects

An electronic musical instrument capable of producing a performance effect resembling arpeggio. Tones corresponding to one or more depressed keys are sequentially produced from the lowest tone or the highest tone and an octave range in which tones are produced is shifted toward a higher octave or a lower octave at completion of each cycle of the tone production sequence. This shift of octave is continued to a certain predetermined octave and, after the tone production in the predetermined last octave has been completed, the tone production is repeated from the original octave or the tone production is conducted with the octave range being shifted in a reverse direction. For realizing simulation of arpeggio, plural key information produced by depressing a plurality of keys needs to be selected in a predetermined sequence. To this end, an up-down counter is employed in an example of the present invention. In a mode of arpeggio-like performance in which the tone pitch sequentially rises, for example, counting in the up-down counter is started from 0 for comparing contents of the counter with the key information and, when there is coincidence, the counting is suspended and the lowest tone is produced in response to the key information. After the lapse of a set time, the counting is resumed for repeating the comparison and a next higher tone is produced. The same operation is repeated until the counter overflows, when the octave is shifted to a next octave. The tone production is made at a predetermined time interval (a regular mode) or at a preset time interval from start of depression of the key (a random mode).