John McCabe's contribution to 20th and 21st Century music in every genre except the grandest of opera is hard to overvalue, for its variety, quality and boundless invention within a consistent self-contained aesthetic. It is often thoughtful or delicate but can achieve great, organically generated, expressive force, seen nowhere more clearly than in the keyboard works. The piano music overall is a hugely rewarding treasure house for performers interested in contemporary repertoire: it contains things that disturb, things that beguile, things that intrigue, things of complexity, things of startling simplicity and virtuosic tours-de-force. While never holding back from making great demands on players' technique or relishing sonoric possibilities, bravura writing is the outcome of thematic development or structural working rather than indulgence in gratuitous pyrotechnics. The greatest masterpieces, are broad in outline, meticulous in detail; the lightest trifles effective and engaging; all are original in concept, technicality and articulation, distinguished by clarity of vision, process and expression, powerful without rhetoric or light without triviality. The commonality of intent in McCabe's kaleidoscopic expressive range lies not in the genre - he was not a slave to genre - but in the mind and imagination of the composer.