With the box-office success of films like Metallica: Some Kind Of Monster - which grossed $1.2m in the US in 2004 - rock documentaries are proving that they are not just the preserve of a niche market of nerdy music geeks. That, at least, was the thinking behind the recent theatrical release of Rewind, a feature-length film charting the rise of Welsh band Stereophonics.

The film, which will be released on DVD in the UK in April, is produced by Document, the London-based television and radio production company that is now branching out into films for the big screen.

"There's definitely a bigger appetite for music documentaries," says Danny O'Connor, who heads Document with Karen Craig. "Five years ago the accepted music film was a concert or at least performance-based material. Now they are telling intriguing human stories through music and performance. Julien Temple set the template and films such as Some Kind Of Monster and DiG! confirmed the trend. It's about story-telling, not just celebrating rock and roll."

He continues: "With Rewind, we started filming the Stereophonics in 2003 but I'd met the band 10 years ago when I made a radio documentary about them and got to know them quite well. It's very much an honest portrait of the band, how they hit the heights, then fell out and then reformed with a different line-up and a new artistic direction."

The release of Rewind follows the screening at the Dublin International Film Festival and the New York Film Fleadh of another recent Document production, The End Of Innocence, about Irish band The Thrills. A warts-and-all look at the music business, that film is "a lesson in humility", according to O'Connor.

Neither Rewind nor The End Of Innocence were originally intended for theatrical release. Rewind was commissioned by the Stereophonics' record company V2 and DVD distributor Liberation Entertainment, which then sold theatrical rights to Vistavega. The End Of Innocence, meanwhile, was financed by EMI.

But that has not impinged on the ability to play on the big screen, says O'Connor. "You have to find a way of marrying up the limitations of budget and the quality of the archive material with the demands of a big-screen audience," he says.

"Although Rewind had a bigger budget than our other films, we were using inherited archive so there are lots of different film mediums and some of it is not always great cinema format. But technology can cater for that and people aren't expecting Star Wars in terms of style with this kind of film."

Document is aiming to work on one theatrical release a year. The company has two projects in the pipeline and will soon announce the first, which will be considerably more ambitious in scope.