Abstract

An auto-accompaniment apparatus, which selects and forms a chord that can be naturally linked with currently generated chord tones from a plurality of inversion variations, and generates the formed chord as the next accompaniment tones, is disclosed.The auto-accompaniment apparatus has an accompaniment pattern memory (1) for storing note data strings for performing an auto chord accompaniment operation on the basis of reference chords, and offset memories (3, 5) for storing tone pitch offsets of the note data with respect to the reference chord in units of chord notes of different chord names in correspondence with a plurality of chord inversion variations and root names. The plurality of offsets corresponding to the chord inversion variations are read out from the offset memories on the basis of a pre-programmed chord progression sequence or chord information detected based on play information. Of the readout offsets, an offset close to the currently generated chord tones is selected by a selector (31). The note data from the accompaniment pattern memory (1) are modified using the selected offset, and the modified data are output to a tone generator (16) as accompaniment information.