Mobile disco: how phones make music inescapable

It's a summer afternoon, and a park in north London is teeming. Scattered randomly across the grass, relaxed Brits of all generations and backgrounds laze on rugs, read papers, and tend disposable barbecues and small children. More active groups play keepy-uppy or show off their capoeira skills. And there's a soundtrack, one you wouldn't have heard even 10 years ago: the buzzing treble of music coming off people's mobile phones. Whether it's Lady Gaga's Poker Face emerging from a gaggle of new parents, or the sharply-attired twentysomethings wearing their choice of Donaeo's funky house anthem Party Hard as ostentatiously as their sunglasses, most groups are playing music off their phones. The revolving mobile jukebox in my group takes us from Johnny Cash to the Knife to Guido. None of these quite work without the bass, but that's OK: it's just nice to have a bit of music playing, right?

Not for everyone. Playing music aloud on mobile phones has become a divisive phenomenon in city life, given its own name by those who resent it: sodcasting. The name, some say, originated in Pascal Wyse's Wyse Words column in the Guardian's Weekend magazine back in 2007: "Sodcast [noun]: Music, on a crowded bus, coming from the speaker on a mobile phone. Sodcasters are terrified of not being noticed, so they spray their audio wee around the place like tomcats."

To say there is a backlash against "sodcasting", that it is felt to be antisocial, is a massive understatement. The fact that the music played is usually hip-hop or other forms of urban music, often seen as threatening by those who don't listen to that music, exacerbates the sense, felt by many, that the very practice of sodcasting carries an implicit threat: "You don't want to mess with me." Indeed, in 2006 a couple of thirtysomethings from London launched a Music Free Buses campaign and a petition asking TfL (Transport for London) to ban the practice. "People think they can sit on a bus and blast music out, and when you ask them to turn it down you get abuse, especially from teenagers," they told their local newspaper. Around 4,500 people signed the petition, and in a poll carried out by the campaigners, 84% said under-18s caught playing music out loud should have their free travel revoked. Only 2% of respondents said they found the playing of music in public acceptable; the same proportion of those polled who were 18 or under. The message was clear: youngsters are the ones sodcasting, and adults despise it.

TfL declined to ban it, though. "We're trying to encourage people to change their behaviour, to be more considerate for everyone's benefit," a spokesman says. "We can't tell people not to do things and have it change overnight." TfL's Considerate Travel campaign features a young character pledging not to play her music too loud, and set alongside her is an older figure promising: "I will try to remember what it is like to be 14 again."

This latter message underlines sodcasting's case for the defence. Recent research suggest a stark generational divide, and more specifically, that attitudes towards playing music aloud in public change dramatically with each passing year. Asked by the social media firm TRU in 2008-09 whether they had played music off their mobile phone speaker to friends in the previous month, 42% of British 12-14 year olds said they had, compared with 35% of 15-17 year olds, and 23% of 18- to 19-year-olds. Bluntly put, teenagers grow out of it; but does that mean they shouldn't be doing it in the first place?

At a bus stop in east London, 13-year-old James is struggling to understand what all the grownups' fuss is about. "If we want to listen to music on a bus, or wherever, it's just a bit of fun. People always want to complain at us." His friend Jamal agrees: "It's not like if you're just playing some MP3s, it means you're going to start [trouble]." But what about adults who just want a quiet life, why should they be subjected to it? "Better get out to the country then!" laughs James, as the pre-rush hour traffic roars down the A10. "It's not a quiet city. At least if you're listening to music, it's, you know, musical."

For Dean "Dexplicit" Harriott, producer of Pow, one of grime's first top 10 hits in 2004, age is key to understanding sodcasting. "It's just great fun to be listening to music while travelling with your friends," he says, adding he's always delighted to hear his own tunes being played in public by young people. "At peak times on the train, coming home from a long day at work, I can understand how annoying it is to have to listen to artists you aren't keen on. But then under-18s raves are extremely scarce these days. Where else can they enjoy music together without a car or club?"

Not at gigs, that's for sure. The Department for Culture, Media and Sport reported that live music was "thriving" earlier this year; but the slight rise in audience numbers stems from mega-venues such as the O2 and Wembley Stadium, where even the cheapest tickets normally cost £50 or more. Young people have been priced out of live music, shooed off the streets by Asbo culture, and are expected to watch MTV or listen to MP3s in their bedrooms.

In the right context, sodcasting can become so much more than sonic territorial pissing contests – I've heard witness accounts of skiving schoolgirls singing along to Kanye West's Gold Digger in rounds ("Two of them were singing the looped sample while one did the rap, switching for each verse. Interspersed with giggles, obviously. It was an incredible moment"), or rapping along with complete strangers on a nightbus to Dexplicit's Pow. Public anger is often down to simple matters of taste; one indie-loving friend who abhors sodcasting in principle admitted he changed his mind when someone enlivened a bus-ride in Coventry with his favourite Bloc Party track. On London buses, I've seen middle-aged gay couples playing South American pop on a wet Saturday afternoon, moody raver mums sodcasting acid house from their glory years; it's not just the preserve of teenagers with attitude problems.

Nor, contrary to popular belief, is it an especially recent phenomenon, says the American anthropologist and musicologist Wayne Marshall, who is currently researching what he calls "treble culture". "Sodcasting could fit into a time-honoured tradition of playing music in public as surely as reggae sound systems or the drums of Congo Square, never mind their antecedents," he says. "Transistor radios and ghetto blasters are both good examples of a longstanding history of people making music mobile. The case of the transistor radio shows that people have long been willing to sacrifice fidelity to portability; while the ghetto blaster reminds us that defiantly and ostentatiously broadcasting one's music in public is part of a history of sonically contesting spaces and drawing the lines of community, especially through what gets coded as 'noise'."

For Elizabeth Schimel, global head of music for the mobile phone company Nokia – which has invested heavily in its "Comes With Music" download service – this international explosion in what she calls "jukeboxing" represents a liberation of music from the private sphere in the west, as well as an egalitarian spreading of music in the developing world. "There are many places in the world where hi-fis are not the norm, and mobile phones are people's portable jukeboxes," she says. "Jukeboxing is huge, the world over. Music [has] become intrinsically woven into the fabric of everyday life, be it on the bus, on a plane, at your desk or in the park with friends."

For Schimel, the speed of the cultural change has been as remarkable as its reach: "The way fans consume music has changed beyond recognition with this generation" she says. "The shift over the past decade has been seismic."

If mobile phones have changed the way a generation listen to music, has it also changed what they're listening to? In the 1960s, producers would famously tailor recordings so they sounded best when feeding through the tiny speaker of a transistor radio. Marshall has been surprised to find that few modern producers and engineers are taking the same steps to make their recordings more compatible with treble-heavy mobile phones. But that's not to say the music isn't changing – or won't change in the future. "I do think that the amount of everyday listening that now happens through tinny laptop speakers and mobile phones feeds into a sort of zeitgeist aesthetics," Marshall says, citing "blog house", a dance music sub-genre popular on blogs – and one with an apt name, as it describes "the sort of electro jams that wiggle their way out of our plastic boxes, sometimes transposing the bass lines into higher registers so as to make them audible".

Dexplicit moved on from making grime hits in the early part of the noughties to the more melodically-inclined bassline, a northern English twist on UK garage that still dominates clubs in cities such as Sheffield and Leeds. Like many British dance producers, he is grounded in a bass-orientated music culture born of the Jamaican influence on UK dance music; a bass culture that underscores dubstep, grime, and its current descendants. So what do you do when people can't hear the bass?

"I've always tried to create a balance in my music, and often have pretty melodies going on upstairs – the treble – accompanied by a nasty low end, the bass." But while the fetishisation of bass among some dubstep fans scales ridiculous new peaks, Dexplicit has noticed a change in production styles: "A lot of producers nowadays are building their tunes around a strong synth riff, as opposed to a distinctive bassline being the integral part of the song. Maybe this is a result of their audiences becoming more accustomed to mid-range music via their iPods? Or maybe they are just toning down the bass to get more radio airplay?"

The possibilities for using mobiles to make music are still at an embryonic stage – but the principles underlying them have a fine pedigree. From punk bands revelling in their "just pick up and play" ethos, to So Solid Crew making half their debut album on Music 2000 for the PlayStation 2, the principle of using low technology to make high art is nothing new – but the technology definitely is. I was recently at a friend's house with a number of young club music producers, including Ikonika and three DJs from Rinse FM, the UK's leading pirate station. Someone jokingly said "let's make a tune", and this quickly devolved into the strangest jam session I've ever seen. DJ Bok Bok used an 808 drum application on his iPhone to lay down a beat, Ikonika and Optimum both used synthesiser applications on their phones to play keyboard melodies, Manara played and replayed a spoken-word "sample" from a YouTube clip on her laptop, and Jam City played the cymbals on a £10 battery-powered "finger drumkit". So that's three mobile phones, a YouTube video, and a £10 toy as the tools for some of the most cutting-edge musicians in the country. Remarkably, it even sounded pretty good.

Mobile phones are also useful to young aspiring MCs, who can play an instrumental beat on the phone speaker, while the MCs gather round, practising their lyrics in turn. This can be great fun to watch, an equivalent to a beatboxer backing a rapper in 1980s New York. "I see this a lot too," says Dexplicit, "and I love it. Nine times out of 10 they probably downloaded the tune for free, which is a downside of phone technology. But it's crazy how fast a tune can spread via the teenage community. They're one of the greatest means of promotion."

The way teenagers use their mobile phones may annoy the hell out of anyone older than 15, but their seemingly obnoxious desire to play music in public needs explaining. To some, sodcasting might seem like a bloody-minded imposition, a two-fingers from those who don't care what others think of them. To the teenagers, though they probably wouldn't put it quite like this, it's a resocialisation of public life through the collective enjoyment of music; it's friends doing the most natural thing imaginable – sharing what makes them happy. And if you try and restrict people's innate instinct to enjoy music together, it just squeezes out from the sides, like an over-filled sandwich.