Weather Report started out as a jazz equivalent of what the rock world in 1970 was calling a "supergroup." But unlike most of the rock supergroups, this one not only kept going for a good 15 years, it more than lived up to its billing, practically defining the state of the jazz-rock art throughout almost all of its run. Weather Report also anticipated and contributed to the North American interest in world music rhythms and structures, prodded by keyboardist/co-founder Joe Zawinul.