What 1969 album by Isaac Hayes is considered a landmark in soul music?

Isaac Hayes’s 1969 album Hot Buttered Soul is considered a landmark in soul music. Its expansive arrangements, deep orchestration, and unusually long tracks helped push soul toward a more ambitious, album-oriented form.

The album was Hayes’s second studio release and contained only four songs. Highlights included a roughly 12-minute version of “Walk on By” and an almost 19-minute treatment of “By the Time I Get to Phoenix,” transforming familiar pop compositions into dramatic, cinematic soul performances.

Hot Buttered Soul followed the weak commercial performance of Hayes’s debut and helped revive his career at Stax’s Enterprise label. It reached No. 1 on the U.S. R&B albums chart and No. 8 on the Billboard 200. Later albums such as Black Moses and Shaft are important Hayes releases, but they are not the 1969 landmark named in the question.