Full disclosure: I'm a gospel-music dilettante—and an agnostic mother-fucker, to boot. For better or for worse, music is my religion, so you may consider me an unreliable narrator with regard to this review of George T. Nierenberg's 1982 documentary, screening at Northwest Film Forum, about two of gospel's most important figures: Thomas A. Dorsey and Mother Willie Mae Ford Smith.

Say Amen, Somebody competently tells its protagonists' inspirational stories, mostly revolving around interviews with Ford Smith and Dorsey (plus family members and musical collaborators). Willie Mae and Thomas were in their 70s and 80s, respectively, at the time of filming, but still sharp of mind.

Dubbed the "father of black gospel music," Dorsey was a prolific composer who is credited with juicing up spirituals and hymns for a broader audience. In the film, he appears wizened with a hangdog expression, but always nattily attired, his speech prone to explosive bursts of emphasis. Despite his advanced age and infirmities, he cuts an imposing figure. His belief in the power of gospel and the Almighty never wavers. "If you don't know God, you need to start over again," he proselytizes, with not a scintilla of doubt.

By contrast, Ford Smith is a much warmer character, and one who had to overcome more prejudices than Dorsey. Even her grandson comes at her with misogynistic bullshit about being against women preachers. At another point, Ford Smith tells a male vocalist in her tutelage, "You got a good voice, but you're throwing it away. Hold it, kind of cup it in your mouth. You can't be a pretty mouth and sing." Pressing her cheeks, she says: "This is like a piano right in here. But you got to do something with it to make it go right. Enunciation is the main thing."

Regardless if you're the staunchest skeptic, you can't help getting swept away by Ford Smith's ebullience. "I feel like I can fly away," she says about her singing. "In my song, I try my best to lift the hearts of people."

Nierenberg appropriately devotes much of Say Amen, Somebody to Dorsey and Ford Smith doing just that at various churches. To nonbelievers like me, many of these songs—besides coming off as a bit melodically stodgy—seem like overblown huzzahs to a godlike entity of dubious veracity. What is a serious life-and-death matter and an ultimate joy to these Christians may strike the heathen as elaborate wishful thinking in song form, transcendently beautiful as it may sometimes be.

However, there are moments in the movie when even godless types may catch the spirit. Say Amen, Somebody climaxes near the end when Dorsey, shortly after breaking both hips, appears at the National Convention of Gospel Choirs and Choruses, and performs with Ford Smith during a hugely emotional service. The rave-up during the final song is a true "holy shit" moment. It turns out that when gospel gets up to 120 bpm and over, even atheists have to hallelujah.