Originally released as the B side of Columbia 45467. The group was pretty audacious to cover a tune that already had a definitive version, in this case by the Spencer Davis Group (featuring writer Steve Winwood). However, you must recall that Chicago was a damn good, multi-talented band back in 1971, full of creativity and genuine rock sensibilities. So they managed to make yet another definitive version. Most of the track is a celebration of the group's drummer and rhythm section, leading slowly back to guitarist Terry Kath's psych-rock chording. This is a like-new copy of the red/black label Columbia Hall of Fame reissue, in its factory sleeve.