Sometimes death, as life, brings strange symmetries. Two music revolutionaries, Sly Stone and Brian Wilson, both died within two days of each other. Each was 82.

Saying farewell to Sly Stone, whose avant-funk vision changed the world and influenced generations of musicians

Sly Stone died after a prolonged battle with COPD, a lung condition that can be debilitating. Here's what doctors want you to know about it.