A spirit of innovation has flourished in American music since the turn of the twentieth century, with composers anxious to throw off the shackles of the European masters and invent new musical languages. Charles Ives captured this early pioneering flair, taken up later by Henry Cowell and John Cage; all initially met with much critical resistance. The same exploratory driving force is equally strong in the music of Carl Ruggles, Edgard Varèse, Harry Partch, Colin McPhee, Lou Harrison and members of America’s youngest composing generation.