Hearts of Space grew out of former architect Stephen Hill’s fascination with space-creating, ambient and contemplative music. Beginning in 1973, Hill hosted a weekly late-night radio program on KPFA-FM in the San Francisco Bay area. What began purely as a labor of love eventually became the most popular contemporary music program on public radio. The program evolved into multifaceted music and broadcast producer encompassing radio syndication, a record company, and an Internet music service.