The world’s greatest innovators are those who are not afraid to experiment, even if it means failing and trying again. The documentary Here’s A Piano I Prepared Earlier takes a look at how intrepid 1960s musicians like Cornelius Cardew, Gavin Bryars and John Cage changed the sound of music by stuffing pianos with hay or leaving the choice of notes up to the rolling of the dice. The result of their experimentation was an unconventional wave of unique musicians.