Production chiefs at film studios have their eyes focused on the box-office results of "Katy Perry: Part of Me," which pulled in slightly more than $10 million on 2,700 screens in its first four days of release, according to Box Office Mojo - a number that neither encourages nor crushes future performance-driven biographical documentaries.

"There are four or six films sitting on the runway," one studio executive said prior to the opening of Perry's picture.

The 3-D film follows in the wake of "Justin Bieber: Never Say Never," which grossed $73 million in theaters last year (according to Box Office Mojo) and revitalized interest in concert films.

Already in the works is a Green Day documentary on the making of its upcoming albums "¡Uno!," "¡Dos!" and "¡Tré!" that could be ready for the Sundance Film Festival in January. Metallica plans to film shows in Mexico City in August for a documentary as well.

While "Searching for Sugar Man" is a prime example of festival exposure leading to theatrical distribution, other music-related programming from the festival circuit has found unique ways to get in front of audiences. "Marley" became the first film to be screened through a link on Facebook; Paul Simon's "Graceland" story, "Under African Skies," appeared on A&E and in Sony Legacy's deluxe editions of the album; and "Shut Up and Play the Hits," Dylan Southern and Will Lovelace's film on the final performance by LCD Soundsystem, will play in more than 120 theaters for one night only (July 18).

"Big Easy Express," featuring Mumford & Sons, Edward Sharpe & the Magnetic Zeros, Old Crow Medicine Show and a train, hopped from South by Southwest and the Los Angeles Film Festival to an exclusive run at iTunes.

"The bands entered into a partnership that said, 'We're all equal,'" says "Big East Express" director Emmett Malloy, who also shot the White Stripes film "Under Great White Northern Lights." "No record labels, just old-fashioned handshakes. All the music was cleared from the start, which gave the company that funded this, S2BN, the unique ability to go out free and clear to [sell the film]. The fact that the film company could supply rights worldwide with no limits like a five-day window made it big."

"Big Easy Express" went on sale June 26 and was not only the top seller among documentaries and music films, but also in iTunes' top 30 of all films for more than a week. It arrives on DVD July 24 with a half-hour of extra footage.

While "Big Easy Express" is riding the online rails, Jodi Wille and Maria Demopoulos are taking their film, "The Source," out for a bike ride. "The Source," which chronicles the Source Family cult in Los Angeles and its band and restaurant, will be the featured film on Aug. 18 at the Boone Dawdle in Columbia, Mo. The event includes an optional bike ride, a party at a winery, the screening and a performance by Chicago band Cave.

"Eventually we want to tour it like a rock band, going further than traditional theatrical by trying to get it into music festivals," Wille says, noting that she hopes to combine screenings with pop-up restaurants and concerts featuring the music of the Source Family band, YaHoWha 13. "We can do it because it appeals to our core audience."

Chicago indie label Drag City ­Records has already signed on to release a soundtrack to "The Source."

Ice-T's documentary on the roots of hip-hop, "Something From Nothing: The Art of Rap," had its world premiere at Sundance and went the traditional route without any bells and whistles. It played 157 theaters for a week in mid-June, grossing $150,000 that weekend, according to its distributor Indomina. The soundtrack, released digitally by Sony, has sold fewer than 1,000 copies, according to Nielsen SoundScan.