Joe Strummer would have been bemused to see, on the 100th birthday of Woody Guthrie, a couple hundred of his old fans gathered in an un-air conditioned church to watch a movie about his old band.

Saturday, filmmaker Danny Garcia brought his film “The Rise and Fall of the Clash” to Washington, D.C. for a one night screening, sponsored by a grassroots group that usually organizes concerts in the space.

It’s an interesting film — great for fans — that explores more fully an era that is only lightly considered in the biggest Clash biographies and scarcely mentioned in others — the time at the end of the band, after Mick Jones had been kicked out, and Joe Strummer, with the backing of svengali/manger Bernie Rhodes, assembled a whole new Clash to tour and record.

It was an awful period that Strummer eventually regretted. But the road to that mistake — said by somebody in the film to be the worst mistake in rock history — comes a long time, as the band became something it never intended — a massive machine that played arenas and squandered studio time with druggy noodling.

Just as it focuses on the end of the band, “The Rise and Fall” also starts at an unusual spot — after the band had formed, and skips rather quickly over their early touring and success.

Garcia said in a Q&A after the screening that the film purposely avoids some of the band’s best known songs because those are also the most expensive to license. Rather, he used snippets from bootleg recordings, with the blessing of Mick Jones, who appears in the film as an elder sage, who can now look back at the ugly period with a wry smile and a shrug.

The movie also is quit different in that it doesn’t focus so exclusively on Strummer, the great rock and roller who has also somewhat been deified since his death in 2005. It was in the Strummer bio film “The Future is Unwritten” that the Clash almost seems like it may as well have been called Joe’s band.

Here, when it comes time early in the film to deliniate what made the band great, fan and hanger on Pearl Harbour says it was Topper Headon, the versitile and powerful drummer first and foremost who made the band rock — nothing the band made without him was worth much, the film seems to say. Paul Simonon is hailed for bringing style and spirit; and Jones for bringing a pure Stonesy rock and roll approach to the band.

But Strummer, eventually noted for his writing, was a rock and roller, too. And indeed, it was when Jones wanted to experiment with burgeoning dance music and hip hop that the band’s different interests began to split the Clash.

The main problem is one that has long riddled rock: When money gets involved and becomes important, all the other ideals seem to fall by the wayside. And after years of working and traveling and living together in such a pressure-filled environment, it’s no wonder bands implode after a few years.

Still, the tension between Jones and Strummer is what made the band forge ahead, and with one of them gone, it seemed to spiral out of control like a balloon losing air. It’s not so different in rock to have a member fired — just last night was the premiere of the rock documentary “God Bless Ozzy Osbourne,” which showed that when Black Sabbath kicked him out it nearly killed him, though he emerged even bigger as a solo act and returned to his old band as well.

Loads of arena bands today tour with new frontmen, though in doing so they’re hired mostly to replicate the old sounds. That’s what Clash 2.0 did as well; in addition to their bad songs on “Out of Control,” they brought back Clash classics on tours that fans like me still liked because they came to our towns.

It’s almost harrowing to hear the stories of the hired hands in the new band in the film. Nick Sheppard and Vince White look like they still can’t believe what happened and White even weeps on camera. Like most of the other talking heads in the film (and those seeing it at the D.C. church screening, as a matter of fact) they appear as a pair of grizzled and haggard old rockers who survived it all.

It’s touching in the end to hear of Strummer desperately trying to get back together with Jones, traveling to Nassau and practically going door to door to find him at one point. And just weeks before his sudden death, Strummer reunited with Jones on stage in a small venue, not unlike this one, St. Stephen’s church.

Unlike “The Future is Unwritten,” in which Strummer’s death permeates the film, it just happens suddenly and unexpectedly in “The Rise and Fall” (though it’s clear from Strummer’s lack of participation in the film that he was gone).

There might need to be a coda on what it all means or the legacy, but fans who will seek out this film will already know how important the band was. And other bands may take as a cautionary tale what happens when you mess with the magical chemistry that make up the great bands.