In this June 24, 2016, file photo, Dusty Hill, left, and Billy Gibbons from the rock band ZZ Top perform at the Glastonbury music festival at Worthy Farm, in Somerset, England. Photo: Jonathan Short, INVL / AP Photo: Jonathan Short, INVL / AP

When ZZ Top came blazing out of Texas in the mid-‘70s, the Village Voice turned up its nose, likening the trio’s sound to “hammered [expletive].”

Actor, musician, and grade-A oddball Billy Bob Thornton sees it a little differently. “It was like seeing Bugs Bunny in person,” says the longtime fan.

ZZ Top has been part of the scenery for so long in this part of the world that it’s easy to forget how exotic they once came across to the rest of the globe. Added to Netflix this month, the 2018 documentary “ZZ Top: That Lil’ Ol’ Band from Texas” peers (barely) beyond the beards to investigate Billy F Gibbons, Frank Beard, and Dusty Hill’s enduring mystique.

It’s a lot more than just Mexican blackbirds and cheap sunglasses, though. To its credit, director Sam Dunn’s 90-minute film — as no-frills, straightforward, and entertaining as the average ZZ Top song — knows better than to expect a great deal of introspection from a band so capable of letting their music do most of the talking.

“I have found the people that I want to play with, and I found that at a very early age,” drummer Frank Beard says as Dunn is starting to wrap things up. “I’m still satisfied with them.”

More Information 'ZZ Top: That Lil' Ol' Band from Texas' Unrated Running time: 91 minutes Where: Streaming on Netflix **** (out of 5)

“Lil’ Ol’ Band from Texas” opens with a collage of rural Texas scenery — falling-down barns, a Texas flag, gas stations, railroad tracks — before picking up a jet-black hot rod heading down a country road. The car pulls up in front of Gruene Hall, and ZZ Top heads inside to jam inside the hallowed Hill Country venue.

Interspersed with interviews and miles of vintage footage, this mini-concert of foundational tracks like “La Grange” and “Brown Sugar” makes the documentary worth watching even for ZZ aficionados: their singular chemistry is as bracing and potent as ever. A handful of today’s top modern rockers, including Queens of the Stone Age’s Josh Homme and Dan Auerbach of the Black Keys, happily profess their admiration.

“They painted this picture of Texas which was totally exotic,” adds Winston Marshall of Mumford & Sons, who happened upon his mother’s copy of 1973’s “Tres Hombres” at age 15. “It was an unimaginable world, totally alien from where I was from in London.”

ZZ Top did not spring from a vacuum, though, but the heady Texas psych-rock scene inspired by Austin’s Thirteenth Floor Elevators. The early moments of Dunn’s documentary feature a wealth of footage from pre-ZZ groups the Warlocks, American Blues, and Houston’s Moving Sidewalks, who toured briefly with the Jimi Hendrix Experience. Gibbons once impressed the guitar god by playing “Foxy Lady” shortly before the Experience was due onstage.

“I like you…you’ve got a lot of nerve,” Hendrix told his young acolyte.

Further enlivening Dunn’s documentary are animated sequences that reconstruct the band’s interactions with Bill Ham, their enigmatic and detail-oriented manager who passed away in 2016. Under his direction, the Texas trio eventually made it big through a combination of incessant touring — once playing for an audience of one in Alvin, south of Houston, and buying the man a Coke to thank him for staying — and high-profile lucky breaks.

The venerable Memphis Blues Festival booked them before the promoter realized ZZ Top was actually three white guys. Upon finding out he put them on last, thinking the audience would have left by then. No one did, and they killed. After “La Grange” became a hit, the Rolling Stones asked the band to open three shows in Honolulu; Gibbons recalls freaking out upon realizing their cowboy clothes screamed “country band” to the audience.

But ZZ’s high-octane sound easily won them over too.

Although it continues through patches of burnout — Beard is exceedingly candid, if brief, when discussing his addictions — and the “Eliminator” videos that made the trio international superstars, the zenith of “Lil’ Ol’ Band from Texas” is probably the Worldwide Texas tour, an undertaking so audacious even media outlets like the Village Voice couldn’t ignore it.

Before “Dallas” and “Urban Cowboy” made Texas semi-chic to the rest of the U.S., semi trailers painted with Lone Star landscapes rolled across America for a solid year and a half. Sharing the 75-foot, Texas-shaped stage with ZZ Top was a frontier-show menagerie that included bison, a longhorn steer, rattlesnakes, javelinas, and a pair of buzzards who took a special interest in Frank Beard.

“If I was playing a slow blues they would get very interested in me,” the drummer recalls. “Like, is he dead?’”

Chris Gray is a Houston-based writer.