Could any group represent the divide between the Sixties and the Seventies better than Sly and the Family Stone? They were the best funk band of the Sixties, mixing up sex, racial politics and an unstoppable groove. The first disc of this masterly collection includes all the hits one would hope for — "Everyday People," "Thank You (Falletinme Be Mice Elf Agin)," "Stand!" — and weaves them into a utopian celebration. But with the advent of the Seventies (represented here on the second disc), the party ended and Sly found the beat in a throbbing hangover. He made his best album, the pessimistic There's a Riot Goin' On (eight of its eleven songs are included here, including "Family Affair," a sweet little ballad about envy), one more great one (Fresh) and then petered out. Sly's endless comeback attempts are summarized here with a few worthy songs, including "Loose Booty," which the Beastie Boys lifted wholesale for "Shadrach."