This three-disc anthology is a curious one, covering the end of the O'Jays' stay at Philadelphia International, the label owned by the group's songwriting and production team, Kenny Gamble and Leon Huff. With the O'Jays as their principal artists, Gamble and Huff refined and defined the so-called Philly Sound, which featured smooth harmonies and lush strings, with just a touch of funk. What makes this collection curious is that its inclusion dates (1976 to 1987) mean that many of the group's biggest and best-known songs from the mid-'70s are excluded. You won't find "Back Stabbers," "Love Train," or "For the Love of Money" here. While there are some monster songs on these discs ("Livin' for the Weekend," "Message in Our Music," "I Can't Stand the Pain"), truthfully this compilation chronicles the O'Jays' slide into disco and irrelevancy. "Used ta Be My Girl" was the group's final Top Five hit in 1978, and the formula appeared to be out of gas by the time the O'Jays left Philadelphia International and signed with EMI in 1987. Die-hard fans will want this set, but most listeners would be better served with a greatest-hits package that includes songs from all phases of their career.