Bluegrass musicians, generally a respectful bunch, have never been known for smashing their instruments at the end of a show. Even The HillBenders don’t feel inclined toward such high-impact dramatics, though the rock-influenced quintet has taken a giant step outside bluegrass norms by reinterpreting a work originally created by classic-rock mainstay The Who. The Who, of course, was the band that brought us splintered guitars and self-destructing drum sets, but it was the same legendary British foursome that delivered the first widely successful rock opera, Tommy, in 1969. Tommy, which tells an often disturbing story about a boy afflicted with trauma-induced deafness, muteness and blindness (followed by further family-inflicted trauma and a brief fling as a religious cult leader), was a gigantic success that signaled a new chapter for the moody British rockers.

Providing the band with its U.S. breakthrough, Tommy would be later retooled for the movie screen and the theater stage, sparking a major hit for Elton John along the way in “Pinball Wizard.” It’s safe to say no one was expecting a bluegrass band to tackle the sprawling rock opus four and a half decades after its initial release, but The HillBenders’ Tommy: A Bluegrass Opry hit shelves in June of 2015 to critical acclaim that included the endorsement of Who guitarist and primary Tommy composer Pete Townshend. The Missouri-based band will be performing the “opry” in its entirety for the Bluegrass Underground concert series, appearing at McMinnville’s Cumberland Caverns on Aug. 20. More than a year after releasing it, The HillBenders are still touring behind the album, which conveys the spirit and energy of The Who’s original while adding acoustic nuances less commonly heard in the rock sphere.

A bit of online digging and a close listen, though, reveals that Townshend’s diverse musical vocabulary does contain some rootsy American influences, though they’ve often been largely concealed by his aggressive, decibel-doused approach to the guitar. Townshend’s early exposure to banjo and mandolin, as well as to the work of country-rock trailblazer James Burton and finger-picking virtuoso Chet Atkins during his formative years, left Townshend with some country strains in his musical knapsack. As attentive listeners may perceive, The HillBenders’ acoustically performed Tommy calls attention to melodies that draw from the same deep musical well as The Who’s country-tinged “Squeeze Box” and “Love Ain’t for Keeping,” a track from 1971’s Who’s Next that rides upon a folksy rhythm, topped with pedal-steel-like guitar licks. Even that album’s ageless rock anthem “Won’t Get Fooled Again,” upon closer examination, displays a surprisingly fiddle-tune-like melody and chord changes prior to its extended middle section, in which Keith Moon’s flurry of drum fills and Townshend’s twin attack of guitar aggression and trance-like synthesizer obscures the country connection.

Key to The HillBenders’ tasteful adaptation is the band’s deft balance of double-time tempos, rock aggression and faithfulness to the arrangements of the original Tommy, never trivializing it or forcing it into a bluegrass box. From the moment the majestic opening overture kicks into bass-slapping, banjo-rolling high gear, it’s clear that a natural intersection of styles, however unanticipated, is at play. In performance, the casual and sometimes humorous commentary from various band members helps the audience keep track of the peculiar story line, effectively lightening the mood without sacrificing a sliver of the original music’s integrity.

Mandolin player Nolan Lawrence’s muscular vocals not only evoke those of leather-lunged Who frontman Roger Daltrey, but wield a deeper, almost operatic beefiness. Guitarist and co-lead vocalist Jim Rea’s lighter-toned voice is an ideal complement, sounding at turns uncannily like Townshend. When the two trade off on the familiar lines How do you think he does it?/ I don’t know! on their rip-roaring remake of “Pinball Wizard,” the effect is vintage Who despite the exhilarating barn-dance vibe. As a unit, The HillBenders are uniformly terrific, though pompadoured Dobro player Chad Graves’ lightning licks and hyperkinetic moves make him the most visually compelling member. His onstage intensity bridges the considerable gap that otherwise exists between rock ’n’ roll’s overdriven physicality and the more reserved demeanor that typically accompanies bluegrass performances.

With its natural acoustic properties and the superb audio production used for capturing Bluegrass Underground’s shows on film, Cumberland Caverns’ subterranean Volcano Room will provide an extraordinary setting for this freshly retold tale of the deaf, dumb and blind boy of rock legend when The HillBenders slide down to the cave’s bottom on Aug. 20. Just maybe, even the bats will see the light.