Premise: Hearts of Stone is the fifth studio album by American rock band Stoneground, released in 1978 on Warner Bros. Produced by Bob Gaudio, it marked Stoneground's return to a major label, having released their previous album, "Flat Out" (1976), on their own label. "Prove It" was released as the first single from "Hearts of Stone".
Hypothesis: Flat out was released in 1976.