There are few greater names in the world of soul than the Isley Brothers. Originally formed in the 1950s as a vocal trio, the group enjoyed moderate success through the proceeding decade, but it was in the 1970s, with the addition of some new members, that they really hit their peak. Taking their funky tendencies to a whole new level, they produced stellar albums like The Heat is On and 3 + 3, which included their now iconic take on Seals and Crofts' Summer Breeze.