All music begins and ends in silence and often there's a bit in the middle, too. Some pieces skirt silence as they hover at the edge of audibility; in others the performers are completely silent. Tom Service ponders silence's fundamental importance to music and how composers have made it an integral part of their works, from classical concert hall to today's avant-garde, from indie pop to techno dance floor. And as he asks if we, as listeners, can ever actually experience real silence, he's joined by composer Michael Pisaro to hear about the implications of silence for him and his audience.