Electronic musical instrument equipped with memorized randomly

Abstract

An electronic musical instrument comprises an accompaniment keyboard; a memory of a relatively small capacity storing a set of accompaniment data sequentially aligned and constituting accompaniment patterns; a read-out circuit to successively read out the accompaniment data from the memory at given clock pulse timings; a judging circuit to judge whether each accompaniment datum read out indicates a predetermined specific value; a random signal generator for generating, independently of the data-reading-out timings, random signals each differing in value with time; an accompaniment data determining circuit to determine the contents of each read-out accompaniment datum when the latter is judged to indicate the specific value in accordance with the signal randomly outputted just when a judgement is made; and a tone generation determining circuit to determine the generation of the accompaniment tone based on the key depression information coming from the accompaniment keyboard and also to function, when the read-out accompaniment datum does not indicate the specific value, to generate regular accompaniment pattern. The instrument performs automatic accompaniments on the read-out accompaniment patterns with random modification of a part of the pattern. Thus the automatic bass and chord accompaniment is realized in non-monotonous, variation-rich manner without a player's temporal manipulation.