It wasn't quite a historical moment to match Tony Blackburn dropping the stylus on to "Flowers in the Rain" in September 1967, kicking off Radio 1 and reshaping Britain's musical landscape. But when Phill Jupitus put on Ash's "Burn Baby Burn" 10 years ago today as the first act of BBC 6 Music – I doubt there was a stylus involved – things also changed, perhaps not as seismically, but significantly all the same.

Two years ago came the announcement that 6 Music was to close, a victim of the BBC Trust's willingness to run scared of the mouthy right's demands for the corporation to trim its sails – indeed, to scupper some of its own vessels if necessary. A few months later it was reprieved following a national outcry that was heartening in its scandalised ferocity, news of the station's imminent demise generating more sound and fury than it had ever done before.

The early days were troubled: I certainly don't remember it kicking off with much fanfare, creeping as it did on to the digital dial, which back then was for the few rather than the many. It began life in 2002, essentially as an advertisement for the DAB digital format. Five Live Sports Extra had been launched the previous month, and 6 Music was followed later that year by Radio 1Xtra and BBC7 (or Radio 4 Extra, as we know it today). But digital radios didn't exactly fly off the shelves, and 6 hit the ground not running but with a bit of a limp. On his first Boxing Day broadcast, Jupitus asked for anyone listening to email him; he got one response.

After a year and a half, the station's weekly audience was just about breaking the 150,000 mark; in the last quarter of 2011 it averaged 1.44 million weekly listeners (for comparison, Radio 1 averaged 11.6 million, Radio 2 14.2 million). In fact, with a 1.2 per cent share of the total UK audience, it's only just behind Radio 3 in the nation's affections. And in its singular way it's not dissimilar in the way it operates: a healthy staple diet of what you might expect but with lashings of stuff you don't.

The uproar over its proposed closure did more than guarantee its existence; it might be said to have been the making of 6 Music. There's nothing like a life-threatening crisis to concentrate the mind, and the station came out of the affair with a stronger sense of its own identity. In fact, conspiracy theorists suspect it was an ingenious PR stunt, that there was never any intention of shutting up shop – and the ratings indicate that if that was the plan, it was a masterstroke.

But who, precisely, is 6 Music for? Do we really need it in the age of the £145 licence fee? Internet streaming services such as Spotify, Mixcloud, YouTube and Last fm allow us access, when and where we want, to archives that bear comparison with the BBC's. The simple answer is that many of us still look for a mediated experience as well. We accept the idea that there are people who are paid good money to turn us on to new things, or old things we've never heard before.

True, when you log on, say, to Spotify, the first thing you get is a string of new releases they think you might fancy; call up a song on YouTube and down the side there's a "more like this" list. But that's a very different experience from listening to a broadcaster whose work you've come to admire curating for you, taking you on a ready-made musical trip, expanding your horizons and blowing your mind.

What, though, does 6 do that Radio 1, Radio 1Xtra and Radio 2 don't? After all, there's some crossover between those four stations. Its target age bracket is the capacious twenties-to-fifties category, which spans a couple of generations, from the children of the Sixties to the children of the Noughties, from the Beatles to Blur and onward to Plan B. It might be said to be the John Peel Memorial Station: the archetypal 6 consumer probably listened to Peel regularly for a significant portion of his or her life. It's true to say that since his death in 2004 Peel has become something of a sacred cow, but with good reason. It's not over-romanticising to say that he stood for artistic purity, for the idea of musical endeavour unsullied by commerce. Nuggets from the legendary Peel sessions are aired daily – in fact, the BBC is sitting on a massive musical archive, and making sure it's fully exploited is part of 6's raison d'être.

Is it sufficiently distinct from the BBC's other music stations, though? One of its unique selling points is the policy of converting artistes into broadcasters. Tom Robinson, Brinsley Forde (Aswad) and Suggs were the first, followed by Marc Riley (who'd lasted a remarkable four years in The Fall in the late Seventies and early Eighties). Since then Cerys Matthews (Catatonia), Huey Morgan (Fun Lovin' Criminals), Lauren Laverne (Kenickie), Jarvis Cocker (Pulp), Don Letts (Big Audio Dynamite) and Guy Garvey (Elbow) have all sat behind the mic, to mostly brilliant effect. They radiate warmth and intimacy and sheer love of music.

This is about more than getting a few big names on board. These people are performers, but they are not, crucially, DJs. It's not patter they're engaged in; they don't spiel like DJs – they talk. And when they have musicians on the show, because they're on the same side of the fence, as it were, they don't conduct interviews – in which a supplicant asks questions of a somehow elevated being – but, rather, conversations between peers. When Jarvis Cocker grilled Leonard Cohen recently, for all the veteran's legendary status it's likely that having headlined Glastonbury with Pulp, the interviewer had probably played to a bigger crowd than the interviewee.

When 6 was under threat two years ago, one of the arguments for closing it down was that its audience could get what they need in the commercial domain. But pretty much the only station that comes close is Xfm: the main playlists aren't dissimilar, though 6 has the eclectic edge. But the argument here for me is what lies beyond the playlist. When Jupitus was hosting the 6 breakfast show, he complained to his Xfm counterpart, Christian O'Connell, that he was allowed only three off-playlist choices per programme; O'Connell told him he got one a week. And there's the commercial breaks: you can't quite see the likes of Cocker, with his moody, languorous Sunday Service, squeezing in between ads for car insurance.

A huge proportion of the new music I'm exposed to comes through 6 – and, more than that, the rich history of popular music's more esoteric byways is brilliantly explored in programmes such as Stuart Maconie's Freak Zone and Freakier Zone. Take the highlights of the latter's February shows: there was the music of the totally out-there composer Harry Partch; 1970s prog-rock concept albums; a history of the electric violin; and a show devoted to wild, unhinged Christian music. On Cocker's Sunday Service you can expect to hear anything from Krautrock to Serge Gainsbourg via William Shatner's legendary Sprechgesang album.