Right now, someone, somewhere on this planet is listening to "Dark Side of the Moon". Released 24 years ago, the album's mixture of passion and misery, blues and electronics has turned on at least three generations of music lovers, fans and musicians.

So far it has sold 28 million copies worldwide, and shows no sign of stopping. It is the third largest selling album of all time. A country the size of Canada has handed money over the counter for it. The album has been in the US Billboard magazine Top 200 album charts for over 1000 weeks beating all known records. It looks as if nobody will ever come close. The next best is also Pink Floyd's "The Wall". It's been on the chart for over 450 weeks. In comparison, "Sgt Pepper" clocked up 200 weeks, "Led Zeppelin IV" under 250.

The phenomenon lifted a medium-sized British rock outfit called Pink Floyd (By the way, which one's Pink?) to global superstar status, where it is still happily ensconced. It's a commercial phenomenon no one has been able to understand, least of all Floyd themselves. How many other albums do you know that deal with insanity, the boredom of daily life, despair and time marching all of us towards certain death? These are hardly topics on the agenda of the likes of Backstreet Boys or Boyzone.

So this year if Pink Floyd, their families, fans and chartered accountants are popping magnums of champagne, who are we to complain? If one in every five households in Britain owns a copy of "Dark Side", who are we to make light of the fact? Even though the band lost millions of pounds when their financial advisors Norton Warbug went bust (they'd invested huge amounts of Floyd's money in a craze that hadn't yet happened - namely skateboarding) the gloom has lifted since "Dark Side" kept selling and selling and selling and selling.

But look at Roger Waters. He's still gloomy. The lyricist who wrote most of the songs on "Dark Side", the conceptualist who created "The Wall" album, the friend who dedicated "Shine On You Crazy Diamond (Wish You Were Here)" to original founder Syd Barrett, is very, very gloomy. Wouldn't you be, if you had lost the legal right to use the name Pink Floyd?

Let us enter a time machine. Let us go whizzing away to swinging London in 1966. Syd Barrett, Roger Waters, Nick Mason and Rick Wright got together under a name taken from a record by Georgia bluesmen Pink Anderson and Floyd Council. Using lightshows to accompany their experimental, spacy music, Pink Floyd quickly became the numero uno psychedelic band of the London underground scene, beating out rivals Cream (Eric Clapton, Jack Bruce, Ginger Baker) and Jimi Hendrix.

One of their earlies hit singles was "Arnold Layne", a song about a transvestite stealing ladies underwear from washing lines. For their first album "Piper At The Gates Of Dawn", Syd Barrett wrote 10 of the 11 songs. These were compositions that clearly showed Barrett's passion for LSD and soon he had become a drug casualty, his mind completely wiped out.

In came David Gilmour, and old school friend, as Barrett's replacement and a year later their second album "Saucerful of Secrets" was released to critical acclaim. Floyd were on their way now, their growing confidence reflected in "More", "Ummagumma", "Atom Heart Mother", "Meddle", "Obscured by Clouds" (albums in chronological order).

Finally came the stereo wet dream for hi-fi snobs worldwide. Nine months of recording time. Alan Parsons as the producer on a measly salary of $35 a week. A cover featuring a spectrum emerging from a prism, no band name, no title. Two and a half decades later the public are still voting with their wallets.

The follow-up to "Dark Side" was released nearly two and a half years later to inevitable critical disappointment. "Wish You Were Here" had one classic track "Have A Cigar", a satire on agents in the rock and roll industry. "Animals", the next album had not a single memorable tune. As their music became less inspired, their concepts grew more ambitious, their stage shows jaw-dropping expensive spectacles.

Roger Waters, lyricist and conceptual director was getting pissed off. Stadium shows were depriving him of audience intimacy. He started isolating himself, and wrote a double concept album, "The Wall" which lacked the lack of connection between a star performer and his audience. It spawned an anthem which passionate yound darlings sing with gusto in Mumbai's pubs, "We don't need no education, we don't need no forced control".