“Everyday Sunshine” is full of vintage concert footage, capturing the band at its full-fathom best. But the story follows a downward spiral, with some grimly comic turns into “This Is Spinal Tap” territory. The film recounts Fishbone’s near breakthrough: “The Reality of My Surroundings,” released the same year as Nirvana’s “Nevermind.” It cracked the Billboard Top 50, and for a moment it seemed that Fishbone might ride the alternative rock wave that made stars of many left-of-center bands.

But even with a spot on the 1993 Lollapalooza tour, Fishbone proved too odd — or was it too black? — for mainstream rock audiences. Soon internal tensions fractured the band. During the recording of “Give a Monkey a Brain and He’ll Swear He’s the Center of the Universe” (1993), Mr. Jones, the guitarist, began behaving erratically, quitting the band to join a religious group in Northern California. Convinced that Mr. Jones needed professional help, Norwood Fisher tried to stage an intervention but was arrested and charged with attempted kidnapping. (He was acquitted in 1994.)

By the time that “Everyday Sunshine” was filmed, Norwood Fisher and Mr. Moore were the only remaining founding members. The film centers on the pair’s volatile Laurel and Hardy partnership and their struggle to keep Fishbone going amid an existence that Mr. Fisher describes as “hand to mouth.” There are poignant scenes of an album-signing event in a nearly empty record store, and of sparsely attended club shows. Mr. Moore is evicted from his apartment and moves back in with his mother; he struggles with alcohol abuse and the toll of constant touring, the life of the “famous but not rich,” as Mr. Moore calls it.

But “Everyday Sunshine” ends on an upbeat note, capturing a one-off concert reunion with Mr. Jones. The band is shown hanging out backstage with Mr. Dowd; Mr. Kibby also recently rejoined. The movie dangles the possibility, tantalizing to longtime fans, of a reunion of Fishbone’s original lineup.

Whatever Fishbone’s future holds, there is no doubt that Fishbone-ism is with us to stay. “Everyday Sunshine” includes tributes by a number of 21st-century stars audibly in Fishbone’s debt, including Eugene Hutz of the Gypsy punk group Gogol Bordello and Ahmir Thompson, known as Questlove, of the Roots. You could add other names to the list of Fishbone’s heirs: the racially and stylistically polymorphous indie rockers TV on the Radio, the Atlanta hip-hop and soul bohemians Cee-Lo Green and Janelle Monáe. Then there’s Outkast, which acknowledged its debt to Fishbone by casting Mr. Moore and Mr. Fisher in its 2006 film “Idlewild.”

In a recent interview Mr. Fisher expressed the hope that the documentary would raise the band’s profile. “Do I think that there’s more possible for Fishbone?” he said. “Hell yes. And there’s more possible doing things our way, without doing stuff that we don’t want to do.”

There’s no sign of compromise on the new EP, “Crazy Glue.” The record leans more toward grooves than tunes, with lots of heavy riffing from the guitarist Rocky George, a former member of the Los Angeles punk band Suicidal Tendencies, who joined Fishbone in 2003. The lyrics have turned inward, away from politics and towards confession, with Mr. Moore singing about his anxieties and personal demons. The results can sometimes drag; Fishbone has never recovered the deft melodic touch that departed with Mr. Jones and Mr. Dowd, the band’s most pop-savvy songwriters.

But Fishbone’s best music is still crammed with energy, ideas and originality. Speed-metal guitars thrash up against New Orleans funk; a slinky reggae verse accelerates into a power-pop chorus, then dissolves into clamorous, dissonant psychedelia. In “DUI Friday,” about a drunk-driving arrest, Mr. Moore croons and bellows over music that brings together metal power chords, a swing beat and jump blues-style brass blasts, with a theremin simulating the whine of a police cruiser’s siren. Like many Fishbone songs “DUI Friday” makes unlikely musical connections feel inevitable, while playing hard times for mordant laughs — turning a lament into a party. At such moments Fishbone is exactly where it has been since the 1980s: freewheeling down its own road, waiting for the world to catch up.