Malkmus is referring to the bassist/singer for Rush, the legendary Canadian progressive rock trio, and Lee’s voice is indeed high—so high that early critics of the band compared it to a “rat caught in a wringer” and “Mickey Mouse on helium.” Yet, as evidenced by Sam Dunn and Scot McFadyen’s probing, detail-rich documentary “Rush: Beyond the Lighted Stage,” (winner of the Audience Award at the Tribeca Film Festival) Lee and his bandmates Alex Lifeson (guitar) and Neil Peart (drums) are more-or-less regular guys.

There should, of course, be an emphasis on “or less.” Dunn and McFadyen have procured a rare assortment of stills and videos from Rush’s early years, as Lee, the son of Polish-Jewish refugees, and Lifeson, the offspring of Yugoslavian immigrants, met as hopelessly inept high school outcasts in suburban 1960s Ontario. The slightly goofier Lee was an anomaly, a Yoko Ono-David Byrne hybrid with ass-length brown hair and a face like an inbred white owl. Lifeson was more the classic rock n ‘roll misfit, a shaggy blonde-haired space cadet comforted by little else but his music(amazingly, Dunn and McFadyen present sepia-toned footage here of Lifeson telling his parents his plans to quit high school for rock music, with understandable repercussions.)

Flanked by drummer John Rutsey, the three performed painfully bad Led Zeppelin knock-offs to high school proms and hand-clapping hippies between 1968 and 1974. Canada was a burnt-out, industrial no-man’s land for musicians, and the group found no stardom until a dreadful “Don’t Stop Believin'”-esque rocker called “Working Man” somehow captivated a Cleveland radio station in 1974. It was around then that Rutsey, struck with a terminal illness, stepped down, and his replacement, the gangly wallflower Peart, helped transform Rush from generic power trio rock into the amalgam of insurmountable musical proficiency and bookish, mystical lyricism that keeps the group selling out arenas to this very day.

Dunn and McFadyen, shirking the woefully familiar rockumentary style of classifying bands as mere rags-to-riches-to-overindulgence case studies, instead whittle the supergroup down to three nerds that know they are nerds. Throughout the film, the band members poke gentle fun at themselves, alternately expressing gratitude and awe at bringing so much over-the-top wonder to the world. Talents as diverse as Billy Corgan, Trent Reznor and Kirk Hammett are on hand here to throw heartfelt adulation right back at Rush, but usually not without simultaneously laughing at the band’s oddities.

Jack Black, for instance, calls Rush “a deep reservoir of rocket sauce.” Hair metal superstar Sebastian Bach, not exactly a literary type, marvels at his being inspired to buy Ayn Rand’s “The Fountainhead,” the themes of which are heavily alluded to on the 1977 album “A Farewell to Kings.” And Gene Simmons of Kiss scoffs at the band’s snubbing a hotel hallway full of groupies when the two bands toured together.

But although “Beyond the Lighted Stage” is scattered with laughs, Dunn and McFadyen manage to avoid outright mocking Rush’s quirky flights of fancy. Nor do they carp, as was the case in last year’s hard rockumentary hit “Anvil,” about the group’s misunderstood genius, since Rush is quite successful (although Corgan at one point them calls them “marginalized” within the realm of early hard rock appreciation, compared to the universally lauded Led Zeppelin and Beatles). The film’s salient point is that Rush was mainstream and against-the-grain at the same time, and it celebrates this duality with a mostly sincere but lightly teasing tone.

Like Patti Smith and Richard Hell and other 1970s New York City punk rockers, Rush achieved success the hard way, through defying easy methods of getting it. Rush’s 1976 release “2112” was intended to be their swan song and middle finger to the increasingly wan demands of their record label, and instead unified a whole subset of pseudo-virtuoso musicians. But while the twenty-minute, seven-part titular track posed an emphatic challenge to ’70s-rock radio homogeny, the music was far too complex and earnest to win over “underground” circles. Rush was arena-equipped from the get-go, and the venues had to be larger than life to capture their epic sagas. Rather than making music by the people, for the people, connecting with the audience through a hands-on, raw approach, their grandiosity made them as far removed from the “common man” as an orbiting martian.

It’s no mystery why fans delight in Rush’s bombastic universe of bass arpeggios, echoing guitar squalls and constant meter-shifting rhythms, often pounded out on a 32-piece, multi-pitched drumset. Aspiring songwriters that base their repertoire around Rush’s are very likely to view music not as a method of pouring out one’s soul, but rather a technical challenge, a way to blow everyone’s mind with how many signature changes can be thrown into one song.

Yet, as emphasized by Dunn and McFadyen throughout this joyous film, such wizardry can ultimately strike an emotional nerve in certain fans. Corgan, a notoriously alienated youth, was nonetheless able to connect with his mother by performing tracks off “2112.” And heavy metal drummers Mike Portnoy and Vinnie Paul obtained musical self-confidence through mastering “La Villa Strangiato,” still considered by most prog rockers to be the apex of musical difficulty. That such power and influence could arise from such innocuous figures as Rush— to this day, they are avid readers, family men, fashion-deprived nerds—is what makes them so charming, no matter how irritated you are by the solemnity of the lyrics, or the pompous, boastful theatrics.

“Rush: beyond the lighted stage” will be in theatres in June.