They came out of the Brewster-Douglass projects, three teenage girls who'd been singing together since junior high -- Diana Ross, Mary Wilson, Florence Ballard -- and for five years they were the most successful American vocal group on earth. Twelve number one hits. More than any group except the Beatles. The dresses got bigger, the wigs got higher, the choreography got tighter, and Diana moved to the front while Mary and Florence stepped back -- a decision that made the group unstoppable and broke Florence Ballard's heart.

The hits were precision instruments. Where Did Our Love Go. Baby Love. Come See About Me. Stop! In the Name of Love. You Can't Hurry Love. You Keep Me Hangin' On. Holland-Dozier-Holland wrote them like they were turning out Cadillacs on an assembly line, and the Funk Brothers played them like the greatest session band in history, and the Supremes sang them like three women who knew exactly what they were worth. "You can't hurry love," Diana sang on the 1966 hit, and she didn't sound impatient. She sounded like someone who'd made her peace with the waiting.

Florence Ballard was the original lead singer. She had the bigger voice, the earthier presence. But Berry Gordy saw something in Diana Ross's thin, urgent soprano -- a crossover appeal that could take Motown to audiences Florence's church-trained power couldn't reach. Gordy made the call. Diana became the focal point. Florence started drinking heavily. By 1967 she was out of the group, replaced by Cindy Birdsong. She died of cardiac arrest at 32, broke and largely forgotten. Diana became the biggest solo star in the world. Mary Wilson kept the Supremes going through lineup changes and declining sales, then wrote a memoir that set the record straight. The songs -- those twelve number ones -- don't care about the drama behind them. They just sound like joy.

The Supremes were Motown's hit machine, but they were also a story about what the machinery cost. Three Black girls from the projects who dressed like queens, danced like they'd been choreographed by the heavens, and sang like every word mattered -- because every word did. The dresses are in the Smithsonian now. The songs are still on the radio. The story is still being argued about.