Napster: Two unwitting teenagers and a cultural revolution

In 1999, a teenage, baseball-capped Sean Parker, future billionaire Facebook investor, told journalists that one day "everyone will be listening to music on their cellphones." It was, he recalls later, "like trying to sell people electricity before the lightbulb was invented."

Downloaded, the story of music-file sharing service Napster, is full of prophetic moments like this, where the company founders, Parker and Shawn Fanning, are already glimpsing a future where fans are streaming music across multiple devices, even as everyone else is popping down to the Virgin Megastore to buy the Spice Girls' CD.

The two-hour documentary had its world premiere at the SXSW music and film festival in Texas, attended by the two Napster founders and the film's director, Alex Winter. The 47-year-old film-maker is still best known for playing Bill S Preston, Esq in 1989's Bill and Ted's Excellent Adventure and its sequel, Bill &and Ted's Bogus Journey, in 1991, as well his role as Marko in 1987's The Lost Boys and for co-directing and starring in the 1993 film, Freaked. But since then he has done very little apart from direct a handful of TV series. This version of Napster's story has echoes of Bill and Ted – two clueless teenagers who unwittingly manage to change history.

Parker and Fanning, from Virginia and Massachusetts respectively, met in an internet chatroom in the 1990s. Aged 17 and 18, they went to California to found Napster, an online community allowing fans to swap music for free. "We were kids who had never been on an aeroplane before," says Fanning. " Suddenly, these artists we idolised seemed to want to kill us."

Fifteen years later, you realise how jaw-droppingly audacious Napster was; in its two years of operation, it peaked at 26 million users, brought the $50bn US music industry to its knees and changed fans perceptions as to whether they had to pay for their record collection. In the film, labels remember themselves as being "ambushed" by these kids; they called them thieves, pirates, gold-diggers. Yet if you believe Parker and Fanning, they were a few teenagers in a tiny office in Silicon Valley who had no desire to re-architect the music business; but if they weren't going to do it, someone else would.

"In 1998, the technology existed to already have an iTunes store, or a streaming service," Parker says. "The record labels knew it, but their whole attitude to this new technology was, 'how can we lock it down, how can we make sure that nobody ever steals a single track from us?' They were terrified. We were just filling a void that the labels had a chance to provide, but refused to. They lost the entire industry because of it."

Napster closed in July 2001 after fighting lawsuits from labels and artists; most notably from Metallica and Dr Dre. But there was no shutting down its ideas. Sean Parker took the notions of community and music streaming into his next ventures, Facebook and Spotify. Napster shaped a landscape that would bring the pillars of the old music establishment crashing down over the next decade.

The excitement of the time is palpable in this documentary, as a musical-free-for-all is unleashed. Parker remembers it as "a golden age for music. I have never seen so much passion for discovering artists as in that year, 1999."

Alex Winter says he made the film "as a Napster fan." Events like Wikileaks spurred him to direct it as "a decade on from Napster, little has changed in terms of the suspicion with which sharing information online is viewed. I wanted to place their story in that context."

What he's done though is capture some of the energy and joy of that time – a reminder of how, recently, the young and the bold presided over a cultural revolution.

'Downloaded' will be released by VH-1 later this year