1. A rhythm creating system comprising: an input means for entering a plurality of parameters specifying the genre and meter of the rhythm to be created; a memory for storing a rule data base for associating the parameters with rhythm patterns including a LEVEL rule specifying complexity of the desired pattern, and a LENGTH rule specifying a number of bars of a rhythm pattern to be created; and a rhythm pattern creating means for creating desired rhythm patterns by an inference system with reference to the rule data base on the basis of the plurality of parameters entered by the input means.
6. A rhythm creating system according to claim 1, wherein said rhythm pattern creating means assigns musical time lengths to the created rhythm patterns.