What do Mike Myers, Neil Gaiman, Duran Duran and the Red Hot Chili Peppers have in common?

They are all mega-fans of the cult, oddball, if-you-know-you-know band Sparks, according to a new documentary from Edgar Wright which premieres at the Sundance festival Saturday.

To Wright and his fellow initiated, the eccentric California brothers that form Sparks have forged one of the most unique and lasting influences on popular music today, with a distinctive blend of poetic lyrics, falsetto vocals and constant re-invention.

Fresh off the success of his Oscar-nominated "Baby Driver," Wright called on his famous friends to contribute to passion project "The Sparks Brothers," which charts the many rises and falls of Ron and Russell Mael over five decades.

"It was pretty easy. People who are Sparks fans are like evangelists -- they want to tell other people how much they love Sparks," the "Shaun of the Dead" director told AFP.

"Sparks are one of those bands that make people want to make art and make music," added Wright.

The feature-length movie charts how a "glam rock anomaly" briefly soared in mid-70s Britain, topped France's charts later that decade, and stormed Los Angeles radio waves with early synth pop in the 80s.

Sparks also left a sizable mark on Germany's club scene in the '90s, got impersonated by Paul McCartney, wrote an upcoming film starring Adam Driver and Marion Cotillard... to name just a few of their varied adventures.

"I felt that the only thing stopping Sparks from being as big as they could be was like an overview, like a documentary, about them, so everybody can understand the context of it," said Wright.

- 'Uncompromising' - 
As the film displays, the Mael brothers have never truly courted mainstream success, constantly reinventing Sparks' sound while remaining "insular... as people and as musicians."

"Neil Gaiman -- we would never (have guessed) in a million years!" said Russell, for whom the movie's eclectic gamut of famous fans came as a shock.

"And Flea, we'd have had no idea that someone as strong of a character as he is -- and stylistically, the Red Hot Chili Peppers -- would be into the band..." he told AFP.

The movie recounts how the siblings flirted with Hollywood once before -- in a 1990s manga film set to be directed by Tim Burton, before he eventually pulled the plug.

They have spent the intervening decades on diverse projects including a collaboration with Franz Ferdinand, a 21-night London residency playing all their albums back-to-back, and a radio musical about Ingmar Bergman.

But the pair, who struck up a friendship with Wright on Twitter, are ready to give the silver screen another stab.

Along with "The Sparks Brothers," they also penned a musical film "Annette" -- "a pretty special and uncompromising film," according to Russell -- for French director Leos Carax, and starring Driver and Cotillard.

- 'Icing on the cake' -
For "The Sparks Brothers," Wright mixed interview footage with archive concert clips, quirky animations and recreations of key moments in the brothers' lives.

The humorous tone will be familiar to fans of Sparks' music, as well as Wright's "Cornetto" film trilogy.

The director's mission to broaden the band's fanbase will depend on the film finding a distributor at the influential Sundance -- America's biggest indie movie fest, which is taking place online due to Covid and runs until Wednesday.

Meanwhile Wright's next fiction movie, "Last Night in Soho" starring Anya Taylor-Joy ("The Queen's Gambit"), was recently delayed again until October, in the hope audiences will be able to return to theaters.

For Sparks, simply creating a standalone film was an end in its own right.  

"Obviously, as a bonus, if a lot of people end up seeing it and having a positive reaction, that's just icing on the cake, too," said Russell.