That would be the Mississippi, specifically, the part that flows through the one-time musical Mecca of Memphis. The documentary takes its structure from the recording of an album that pairs up various Stax records legends (Bobby Bland and Mavis Staples are just two of the standouts) with more modern artists (Snoop Dogg, Al Kapone) The new kids stopping by the old school to pay homage. There's some talk about the collaboration's significance, and there's some racially charged history to relate, but the real point is to hear these oldsters one last time, to remember and maybe even discover what they gave us. Sonically, there are highlights throughout. But for filmed story, the best bit comes at the end, when a bunch of kids from the Stax Music Academy sit down with William Bell and Snoop to record "I Forgot to Be Your Lover." Narrated with great portent and sweep by Terrence Howard. (2014) — Matthew Lickona