In honor of Motown's 50th anniversary, we asked Duke Fakir, the only living original member of the Four Tops (who'll receive a lifetime achievement award at next month's Grammys), for his ultimate Hitsville playlist. He had a lot of great songs to choose from, which he credited, at least in part, to the fierce-but-friendly competition that existed in his Motown family. They used to bet on whose songs would hit No. 1 first: ''It started with the producers, then the engineers got in on it, then we the artists got in on it,'' Fakir says. ''It was really great for the company because it kept raising the bar. When we'd get in that studio, we would work to outdo. The producers would be outproducin'. The engineers would go up into the third floor and try to fix the echo chamber for us to sound better. [Laughs] They weren't big bets, but it was a bet.''