ON EASTER Monday, REM performed a concert at the Royal Albert Hall in London, carried live on BBC Radio 2. The band played the old favourites, of course, but they also dipped into their new album, Accelerate. It wasn't in the shops at the time of the concert. In fact it still isn't: the CD is released tomorrow. Yet many of the fans who attended the Albert Hall will have travelled there listening to it on their MP3 players or car stereos. How? Because REM, in their wisdom - and I use the word advisedly - released the album for free on the social networking site iLike the same day they played London. Or not quite for free: it cost fans nothing to listen, but they still had to pay to download the 11 tracks.

"It was one of those ideas that was presented to us and it seemed like a good one, so we ran for it," REM's Michael Stipe said ahead of last week's launch. Talking about the huge effect the internet has had on the way people consume music today, he added: "you can either go with it or sit back and watch it happen."

REM, it seems, are going with it. But theirs is only one first among many. Radiohead set a precedent of sorts last autumn by releasing their new album, In Rainbows, on the web and asking fans to pay what they thought it was worth. Moreover, they announced the release just days before it happened. It was also available in physical format - industry jargon for something you can hold in your hand - but not until several weeks later. Last month, meanwhile, cult US rock band Nine Inch Nails followed suit when, completely without warning, they released a 36-track instrumental album called Ghosts I-IV via their website. Volume One is free; the others are priced between $5 and $10. There are also deluxe CD sets priced at $75 and, for the die-hards, a $300 limited edition boxed set.

It might be interesting, but this isn't the measured and controlled way that the music industry is used to going about its business. And there's more where that came from. Prince's most recent album, Planet Earth, was given away free with a British Sunday newspaper and he handed out more copies to the 140,000 people who attended his 21-night residency at London's O2 Arena last summer. Earlier this month, The Charlatans made their new album, You Cross My Path, freely available on their website. To date, there have been more than 60,000 downloads. Not to be outdone, Madonna's new album, Hard Candy, will be available as a mobile phone download on April 21, a week before it hits the shops in CD form.

Finally there are rock supergroup The Raconteurs and hip-hop duo Gnarls Barkley, who both released new albums this month. Gnarls Barkley's The Odd Couple hadn't been expected until April, but popped up on iTunes on March 18. Within two days of its digital release, it was number one in the US download chart. A CD version is released tomorrow. However, nobody even knew there was an album in the offing from The Raconteurs, whose members include Jack White of The White Stripes.

The Raconteurs album is called Consolers Of The Lonely, and it was released on all formats last Tuesday. Recording was only completed at the beginning of March and the master tapes were taken immediately to, first a vinyl pressing plant, then a CD pressing factory. The band's initial plan had been to simply have their label, XL Records, deliver it to shops unannounced on March 25 while making it available for download at the same time.

"The purpose," the band wrote on their website, "was to get the album to the fans as soon as possible. We wanted to get this record to fans, the press, radio, etc, all at the EXACT SAME TIME their emphasis. We wanted to explore the idea of releasing an album everywhere at once and THEN marketing and promoting it. The Raconteurs would rather this release not be defined by its first week's sales, pre-release promotion, or by someone defining it FOR YOU before you get to hear it."

The deliberately blurry black-and-white photograph on the album's front cover shows band members dressed up like turns in a 19th-century American vaudeville show. On the back, drummer Patrick Keeler holds two blank CDs in his hand. A message of encouragement to the fans? Two fingers to the industry? Who knows. Interestingly, the band also recommend listening to the record on vinyl.

In the end, however, the surprise attack The Raconteurs planned wasn't viable. The retail outlets required some prior warning, so an announcement was made on the band's website on March 17 stating that the album would be available in a week's time. Even so, the speed of it all has been unprecedented.

So, REM's album sits on a social networking site along with thousands of unsigned bands; Gnarls Barkley premiere theirs as a download only; Prince gives his away free; Madonna's comes on a phone; and The Raconteurs keep the whole process secret until the last moment. What's actually happening here? Are gimmicks and stealth releases going to become the norm? No, insists Gennaro Castaldo of music retailer HMV.

"I don't think it will become a pattern, because ultimately it doesn't work in the interests of the record labels," he says. "Things like this work as an exception to the rule because they stand out and they generate publicity. But of course if everyone tried to do it that way, it would be chaos and you wouldn't have the structured release schedule that, ultimately, benefits everybody."

Like every other retail outlet, HMV had only a few days' warning about The Raconteurs release. Unlike the supermarkets, which account for a sizeable number of CD sales, they didn't require six weeks' notice to stock it. The result? HMV won a 70% share of sales of the album on the opening day simply because their stores were among the few places it was available. That's good for HMV, of course. Less so for the consumer or the label.

"There will be other bands out there thinking, What can we do that will allow our release to stand out that's a bit quirky, that allows us to speak to our fans in our own way'," says Castaldo of this spin on guerrilla marketing. "But soon they're going to run out of anything new." Besides, he adds "look at the names of the people involved - Radiohead, REM, Prince, The Raconteurs. They're all iconic artists so, in a way, they're in a position to do it. The media sits up and takes notice and it works for them. But the vast majority of artists don't have that luxury."

That's all true, of course. But as downloading grows in popularity, is the very notion of the album itself being questioned? As we know it, the long-player is usually a suite of 10 or 12 songs weighing in at around an hour, and packaged with photos, lyrics and adverts for ringtones. It is written over many months and recorded over many weeks, yet it appears as if fully formed on a day appointed by a record company. But with the digitisation of music and its easy availability over a phone line, we no longer need the album in that form. Songs can be issued serially as they are created which means the chronology is exact and honest, and the stylistic progression visible - or at least audible. Of course, the prolific Prince tried something similar in the 1990s but his label, Warners, stopped him. As a result, he invited ridicule by appearing with the word "Slave" inked on his cheek. Now he looks like a man ahead of his time.

Of course we've been reading the last rites to the album for decades now and, in truth, it seems likely to survive well beyond this one. The internet offers exciting possibilities but doing away with the album entirely may be a step too far for most established bands. Though they may wish to lessen the time between completion and delivery, they will still prefer their songs to be sold as a collection. Whether that's in the form of a 60-minute CD or a bundled download won't really concern them much; what will is that the album remains as a concept, even if it has no physical form.

One reason both bands and labels need albums is for touring purposes. Along with merchandising and branding, this accounts for a not inconsiderable slice of a band's income and it helps to have a set of new songs to play alongside the old ones. Sell out the Royal Albert Hall, fill its corridors with stalls selling official tour T -shirts at £20 each and you can almost afford to give the music away free. As for album downloads, they still don't amount for a great deal of the album market, says Castaldo. Neither do they count towards the UK album charts. So Gnarls Barkley can raise awareness of their new album by making it available as a download first, but it is only ever a marketing exercise ahead of the release of the physical product.

"People like the idea of downloading," says Castaldo. "They like to burn their own copies, create their own playlists. But at the same time, if you're a fan of a certain artist, you also like to own the album at source. So if Gnarls Barkley release their album as a download a couple of weeks ahead of the physical release, all that can really do is help the sales of the album when it is released."

To some that will smack of complacency, to others it will seem pragmatic and realistic. The only thing we can say for certain is that the music will always be there.