None of the music here pretends to be subtle. The mystical flavour of Henry Cowell's atmospheric Synchrony takes the Stravinsky of The Rite of Spring a stage further, while the sometimes grandiloquent Piano Concerto makes use of Cowells' favourite device, the note cluster. Lou Harrison brings Far Eastesrn influences to bear on his hybrid Concerto for Organ with Percussion Orchestra, and the alternating tumultuousness and reflective quality of Varese's Ameriques vividly tells of the wonders of the new world. The San Francisco Symphony and Tilson Thomas give scintillating performances.