As a member of the Grateful Dead, drummer Mickey Hart took a strong interest in percussion's place in music from around the world. His non-Dead work features a wide range of Native American, Indian, African, and Brazilian musicians; he, in turn, brought all those influences into the Dead. Hart's musical studies inform the complex instrumentation on his albums, though some of them remain quite personal: 1989's Music to be Born By, a section of which appears on our playlist, finds him jamming with a recording of his as-yet-unborn son's heartbeat.