This is one of the boldest pieces of programming to have come my way in a long time. We hear far too little of the myriad output of Henry Cowell, which encompasses works that even now sound radical and experimental, along with highly conservative scores of homespun yet noble simplicity and yet others anticipating and embodying future concepts of ‘World Music’. The startling Synchrony, intended as a dance work for Martha Graham, and the percussive, dissonantly virtuosic Piano Concerto (both 1930), with their Ivesian fusion of polyharmony, tone-clusters, rhythmic complexity and jazz inflections, are definitely among Cowell’s most successful syntheses of his various experimental tendencies. Harrison’s extraordinary Concerto for Organ with Percussion Orchestra (1973-74) is if anything an even wilder, yet more unlikely, but stunningly effective piece. Jeremy Denk and Paul Jacobs are the bravura soloists in the two concertos. Still Varèse’s Amériques, heard here in its 1927 revision, with its sirens, Lion’s Roar drum and ranks of percussion and inspired mosaic of form, remains the Granddaddy of the spirit of adventure in American music, and Michael Tilson Thomas turns in a superb performance, remarkable as much for the delicacy of the quiet moments as for the raucous climaxes.