American female vocal soul sister-trio formed in 1968, Chicago. They released their two first albums at [l=Stax], produced by [a=Isaac Hayes] and [a=David Porter]. They switched to [l=Columbia] in the mid 70's. Their association with [a=Earth, Wind & Fire]'s [a=Maurice White] brought them at the top of the charts with "Best Of My Love". They had big success as well with "Boogie Wonderland" sang with [a=Earth, Wind & Fire].