MyJazzBand

MyJazzBand is a MIDI jazz accompaniment generation application that incorporates intelligent jazz chord and scale analysis, a modern native Mac OS X Cocoa user interface, Band-in-a-Box file format compatibility, and much more.

MyJazzBand can import chord sequences from Band-in-a-Box files. This lets you use BIAB files you already have and the large number of BIAB "real-books" you can download from the Internet.