Mash hits: Theart of the mash-up

Last week's riots made an unlikely star out of Upinder Randhawa, a presenter on the previously little-watched Sikh satellite channel, Sangat TV. As regular programming was abandoned in favour of live footage of Randhawa hurtling around the West Midlands in a car and breathlessly reporting from trouble spots, the thousands of us tuning in were regularly confronted by an infuriatingly catchy advertisement for an Indian cooking product, KTC Pure Butter Ghee. While KTC reaped the rewards of its unexpectedly successful campaign, the knee-jerk response from myself and others wasn't "Wow, look at that advert", but "What can I do with that advert?". By the next morning new versions featuring the cheery "Mmm! Parathas!" had been uploaded to YouTube. It just seemed to be the obvious thing to do.

Over the last decade, this kind of reappropriation and reworking of other people's creative work has become endemic. Whether it's for musical kicks, belly laughs or to make political points, digital delinquency is rife – and it's incredibly popular. A cut-up video of MasterChef presenters John Torode and Gregg Wallace set to thudding beats is currently in the UK Top 40; Amnesty International recently commissioned online pranksters Cassetteboy to produce a video mocking Barack Obama's policy on Guantanamo Bay; all manner of cut-ups and resplicings are going viral online every day of the week.

New British laws enshrining the right to produce satire and parody using other people's work (as proposed recently by Vince Cable) seem almost unnecessary; we're doing it anyway – and the people who are being made fun of and whose copyright is being violated seem to be growing more sanguine in their response. Mashup culture, once a niche activity, is now mainstream.

Its development can be closely pegged to that of technology. Musique concrète in the 1950s was inspired by the capabilities of the gramophone, while in the early 1970s twin record decks enabled one of the founding fathers of hip-hop, Kool DJ Herc, to mix together sounds by James Brown and the Incredible Bongo Band to the delight of the crowd. Ten years later, as Clubhouse clumsily mixed Michael Jackson's "Billie Jean" with "Do It Again" by Steely Dan, the arrival of digital audio saw the Art Of Noise use expensive Fairlight computers to manipulate the harmonies of the Andrews Sisters into new and dizzying shapes.

By the late 1980s this sampling technology had become as cheap as guitars. Albums such as Licensed To Ill and Paul's Boutique by the Beastie Boys became not only landmarks of culture plundering, but also a musical inspiration to others. Satirists embraced the same technology; the San Francisco experimental outfit Negativland mocked U2 by lifting huge chunks of their recordings, while Chris Morris's painstakingly compiled audio trickery on his radio shows sent budding satirists scurrying to their cassette recorders.

"He was our main inspiration," says the semi-anonymous Mike, from Cassetteboy. "We started making compilation tapes for our friends that included snippets of dialogue. Those snippets got bigger, we added loops and sound effects and it just evolved from there."

Swede Mason, the publicity-shy Yorkshireman behind "MasterChef Synaesthesia", was similarly awestruck as a teenager by the possibilities of the cut-up technique. "The first thing I did with a sampler was take that bit from the Flash Gordon film where [former Blue Peter presenter] Peter Duncan shouts 'Spare me the madness'," he says. "I just looped that for about 45 minutes. It was crap, but there was some kind of concept behind it, and that's when it clicked. Since then it's just got cheaper and easier." The PC and Mac brought the means of production within the reach of millions and by the end of the 1990s a mass of self-taught digital musicians and artists were sampling, looping, Photoshopping and reworking.

"Before that, [imaging] technology was only available to super nerds," says Rob Manuel, of B3TA, the renowned online playground for manipulators of GIFs and JPGs. "We had to wait until PCs could display enough colour to fiddle with photographs. But the real change wasn't about the means of production, but distribution. Once pictures could be emailed, it became massive." Here was one of many internet-based revolutions;an audience of millions and negligible cost of reaching themsaw a creative explosion. Fierce campaigning began by groups advocating the idea that information "wants to be free".

The Evolution Control Committee's "Rebel Without a Pause", an alliance of Public Enemy and Herb Alpert produced in 1993, became a mashup landmark and a flag-waving protest against copyright law. It opened the door to so-called "bootleg" artists such as Roy Kerr (The Freelance Hellraiser, the man responsible for the mashup hit "A Stroke Of Genius", which sampled The Strokes and Christina Aguilera). And superstars such as Jay-Z, with his sample from Annie for "Hard Knock Life (Ghetto Anthem)", were also getting in on the act. But some artists and songwriters were becoming increasingly distressed at the violation of their copyright. In the early 1990s, De La Soul and Biz Markie were two of many rap artists hit with lawsuits for lifting other recordings wholesale for use as backing tracks. But when a judge pronounced in 1993 that 2 Live Crew's use of the riff from Roy Orbison's "Pretty Woman" qualified as a parody, it meant that lifting the guitar riff was "fair use" – a concept enshrined in the US Constitution but nebulous in its definition.

The makers of Star Wars, for example, might not like the endless mashups using Darth Vader et al, but keeping up with the flood of videos made by fans must be a Sisyphean task. And while "fair use" is now a phrase used incessantly by those defending mashup culture, the concept doesn't loom large in their minds; they're simply having fun.

"We just hoped we'd get away with it," Cassetteboy says. "Our first production used Otis Redding and Tim Westwood samples, but when we didn't get sued for that we just became more confident. We figured, well, what's the worst that could happen? There are no profits to share, suing us would just draw attention to us."

Not everyone gets the joke. Cassetteboy cites the mysterious removal of their Nigella Lawson cutup from YouTube but give credit to Lord Sugar: "When we made our video of The Apprentice, he took it on the chin."

Mashup artists certainly aren't in it for the money. Swede Mason says: "I'm not interested in being famous in any case. Right now I'm at work plastering walls. I only make videos on Mondays because I'm on a building site the rest of the week. I'd like to make a bit of money, sure, but not loads – just enough to be able to do it more often. That MasterChef video probably took me a year to make. I shelved it for a while because I just couldn't stand it any more, and to be honest I hate it now. Well... I love it really – but you wouldn't believe how many times I've had to watch and listen to that thing." Mason says he'd have been happy if it had received 2,000 views; it currently stands at over two million.