Insistent beat. Soulful rhythms. Hallowed vocals. “Race music,” as it was coined in the early 20th century, combined gospel, blues and jazz for a sound uniquely, indisputably African-American. Once the term was changed to rhythm and blues, all races (read: White folk) started buying in and imitating the rhythmic sounds native to Blacks. Memphis was particularly fertile ground for musical talent, attracting blues and soul artists from the Mississippi Delta.

The sounds of Memphis artists like Otis Redding, William Bell and Bobby “Blue” Bland, influenced rock and roll artists on American soil and across the pond. Soon, Black and White artists were working together to create historic sounds and iconic collaborations. From Booker T. & the M.G.’s integrated band to the hip-hop artists of today (if only through sampling), the sounds of Memphis maintain an important cornerstone of American soul music.

Take Me to the River, debuting in theaters September 12, showcases the inter-generational and interracial influence of Memphis music. Directed by acclaimed music producer Martin Shore, the documentary serves as a living album, bearing witness to historic musical collaborations like the remake of Bill Withers’s “Ain’t No Sunshine” with Memphis blues legend Bobby “Blue” Bland and rap artist Yo Gotti.

Snoop Dogg shows his love for the Memphis sound by dropping a few verses on a great remake of “I Forgot to Be Your Lover,” with the song’s original crooner, William Bell. The film features several live performances, each baring a unique take on an old classic, each building a bridge between generations.

Terrance Howard narrates while contributing to the soundtrack via vocals and guitar. Take Me to the River focuses on historic Stax Records, one of the first integrated record companies. Rivaling Detroit’s iconic Motown, Stax gave us Isaac Hayes, the Staples Singers, Rufus Thomas and more. The film balances the heavy history of a segregated Memphis with behind the scenes footage and recording sessions of many of the soundtrack’s artists. Those artists, some with careers spanning over 40 years, provide light entertainment and insight behind some of R&B’s greatest hits.

The film invites us to watch these legends in action, part reality TV, part simple history lesson. When interviewees delve into the painful past of segregation, the demise of the Memphis music scene, and the death of Rev. Dr. Martin Luther King Jr. at their doorstep, the energy comes right back up with a quick jam session to keep us focused on the joy of music.

The cast of hip-hop artists is refreshing. There’s a genuine respect shown toward their elders and humility absent in most of the interactions we see among hip-hop peers. They listened while the elders spoke, shared stories about their careers, and finally worked together to put a new spin on classic hits. The Oscar-winning MC Frayser Boy (who collaborated with Three 6 Mafia on “It’s Hard Out Here for a Pimp”) shyly told blues legend Bobby Rush about his Academy Award win. He was humble. Rush was genuinely proud. There was nothing braggadocious about it.

But Take Me to the River is more than a gathering of old men, literally. Mavis Staples graces the screen with her husky voice and an easy rendition of The Staples Singers’ “I Wish I Had Answered,” a welcome ode to the traditional call and response native to African-American culture. Additionally, Lil P-Nut joined the cast to collaborate with Otis Clay on “Trying to Live My Life Without You.” He also got solid advice from Bobby “Blue “Bland, who died before this film was complete.

You don’t have to be a musicologist to enjoy this film. It’s not a strict lesson in R&B music history, nor is it laden with lengthy advice about where the genre is headed. There’s nothing studious about this documentary, and that’s a great thing. Take Me to the River is a journey, a backstage pass for people who enjoy music. I personally wasn’t familiar with all of the names, but enjoyed every session and was thankful for the important but brief bits on the background of Stax Records and the various Memphis and Mississippi Delta artists.

Take Me to the River is set for a limited release on September 12, in Los Angeles, New York and Memphis, with other cities to follow. The soundtrack dropped yesterday, featuring 12 songs from the documentary.