Does fusion music eat its young? Or, to put it differently, will success spoil jazz-rock musicians? These recent recordings by the four ex-members of Return to Forever suggest the dangers that lurk when a popular "supergroup" attempts to subdivide itself into autonomous superstars.

Drummer Lenny White and bassist Stanley Clarke have, for the moment, fallen flat on their faces. Lenny White Presents...

In 1969, Miles Davis was looking for a way to sell more albums. So the jazz trumpeter delved into rock and R&B on Bitches Brew. When his record sales promptly increased, fusion was born.

Eight years later, the genre is having an identity crisis. Once, pegging fusion was easy: it was the rigorously creative effort of Miles Davis, his former sidemen (Tony Williams, John McLaughlin, Herbie Hancock,...