One Man Band is the software version of the digital music instruments known as arranger keyboards, home keyboards and workstations. It creates auto-accompaniment based on the played chords and it adds auto-harmony to the played melody. Chords and melody can be played in realtime in the Live Window, with or without a connected MIDI keyboard controller or pre-entered in the Sequencer Window. It utilises standard style files compatible with the styles used in Yamaha PSR, DGX and Tyros arranger keyboards. There are thousands of these styles available on internet and the included style editor can be used to tweak existing and create new styles.