MAVIS! is the story of how a little girl with a big voice journeyed with her family from Mount Zion Church in Chicago to Stax Records, where The Staple Singers became “God’s greatest hitmakers”.

The sensual spirituality of Mavis Staples’s husky contralto continues to take audiences into ecstasy with the combination of faith, family, and freedom that has characterised the music she has made, both with The Staple Singers and solo, throughout her lengthy career.

Mavis and her sister Yvonne, the sole surviving members of The Staple Singers (who also included their father, Pops, elder sister Cleotha, and brother Pervis), tell their absorbing tale with verve, humanity, and sentiment, interspersed with archive and concert and rehearsal footage, and interviews with collaborators and those they influenced.

At 75, although claiming to no longer be as frisky as she once was, the indomitable Mavis captivates with her groundedness and down-to-earth sense of fun.

The story of the Stapleses is one of the strength that faith and family provide for the long walk to freedom. While the tale and its telling involve anger and loss, it is ultimately, as Mavis states emphatically at the beginning of her concert, about joy, happiness, inspiration, and positive vibrations; and the tears that it inevitably evokes are tears of joy.

As such, Jennifer Edwards’s documentary is an emotional tale and trip combining elation in the gospel with defiance of discrimination, as the group crosses boundaries — first, by combining blues, country, and gospel to create their unique sound, and then by merging spirituality and social comment at civil-rights marches and the Newport Folk Festival, before re-sacralising soul as Stax stars in the Black Power period characterised by the Wattstax Festival of 1972, a benefit after the Watts Riots in 1965.

Although they made the transition from the gospel circuit to secular labels and the pop charts that was also made by many other soul stars, they, uniquely, did so without secularising their music and message. The freedom and message songs they sang were rooted in and integrated with their faith. As Pops said, on first meeting Martin Luther King at Dexter Avenue Baptist Church in 1963, “If he can preach it, we can sing it.”

Others, like Aretha Franklin, recorded secular content and the occasional gospel album, or, like Marvin Gaye, fought commercial pressures to make one classic album combining social comment and spirituality. The Stapleses, by contrast, consistently delivered a blend of social comment, spirituality, and soul.

Those inspired or influenced by Mavis’s journey and who feature in this documentary include Bob Dylan (who proposed to Mavis in the early 1960s), The Band (who acknowledged the influence on their harmonies by including The Staples in The Last Waltz, the film of their final concert), Prince (who signed Mavis to his record label and produced two solo albums for her), Bonnie Raitt (who has toured with Mavis), and Jeff Tweedy (who collaborated on two solo albums and a posthumous release by Pops).

While the voice of the youngest Staple Singer stood out from the beginning, the classic Staple Singers sound was always collaborative, Pops bringing the blues timbres and licks, Cleotha, the country sound, and Mavis, the gospel/soul roar. When The Staple Singers finally ended with the deaths of Pops and Cleotha, Mavis needed collaborators — beginning with sister Yvonne, and extending to Ry Cooder, Jeff Tweedy, and M Ward — to carry on with her natural style and verve.

The final collaboration with Tweedy brings the story told in this documentary to a moving conclusion as he takes recordings made by Pops, and adds backing and the harmonies of the remaining children, to create what is in essence a Staple Singers album fashioned 15 years after the death of Pops and fulfilling the promise made by Mavis to her father not to lose this music.

As Tweedy, Mavis, and Yvonne listen to this album, harmonise, and reminisce, a profound sense is formed of an unbroken circle in which the songs of childhood — hymns of faith that made them strong — are sung while hearing the angels sing along.

Dogwoof have released the film in theatres in the UK. See www.mavisfilm.com/watch for dates and venues of screenings. Mavis! is available now on iTunes.