Preludes Inégales, named after the improvisatory group Notes Inégales, of which Butler is a member, explores ways in which material that has its roots in improvisation can be captured and worked on in more formal and strategic compositional ways. Butler then extends the process by improvising again on the composed material, 'composing' again - and so on. This unique approach to composition has resulted in this characterful set of preludes for solo piano.