Roger "Syd" Barrett was the lead singer, guitarist and spiritual leader of the Pink Floyd for a very brief period in the band's scheme of things, from its origins in 1965 through his low-key ouster in early 1968.

Yet without him, there would have been no "The Dark Side of the Moon," "Wish You Were Here," "The Wall" or any of the '70s monster hits created by the band he named, drawing inspiration from two obscure blues artists in his album collection.

Syd, who died this week at age 60, set the early version of the band apart from its would-be competitors by using his guitar as a free-form device, exploring its sonic possibilities at a time when advances in amplification allowed for all kinds of strange sounds that were previously unheard. He also took an approach to songwriting that followed its own path, drawing from extraterrestrial influences and fantasy scenarios that gave many of his tunes an otherworldly feel.

The most enduring example of his work is "The Piper at the Gates of Dawn," the Pink Floyd's debut album, which wan't even given a proper American release until it was committed to compact disc in 1987, 20 years after its release. The opening track, Barrett's "Astronomy Domine," also opened shows in 1994 on Pink Floyd's last tour to date, and hearing the song was a real treat for many fans who never though they'd hear such material performed live. Syd wrote or co-wrote most of the tracks on "Piper," including the bizarre closer, "Bike." The end of the song is a rather disturbing sound collage, complete with quacking ducks, that seems to signal something was going amiss for Mr. Barrett.

Unfortunately for him, 1967 was something of a high-water mark for the "anything goes" attitude that pervaded the Pink Floyd's home base of London, and Syd apparently indulged a bit too much in everything that was available. His performances throughout the second half of the year became increasingly erratic; it's reported that during some shows, he'd do nothing besides play a "C" chord on his guitar while the rest of the band covered for him. And in one unnerving incident, he was interviewed by Pat Boone for his TV show, only to greet Boone's soft-toss questions with a catatonic stare.

Finally, his bandmates - Roger Waters, Rick Wright and Nick Mason - figured that if they were going to survive in the pop music world, it would have to be without Syd. The group's final single with him, "Apples and Oranges," may have appealed to some of the more adventurous listeners of the time, but frightened away most of the record-buying public. And his next two songs in the can, "Vegetable Man" and "Scream Thy Last Scream (Old Woman With a Casket)," were even further afield commercially.

Around the end of '67, a new guitarist - Syd's friend David Gilmour - started playing shows with the Pink Floyd. Barrett stayed in the lineup for a while. But before one concert, the rest of the band decided not to pick Syd up, and that was that.

He did record two solo albums, "The Madcap Laughs" and "Barrett," both with heavy input from Pink Floyd members. And one last song of his appeared on "A Saucerful of Secrets," Pink Floyd's second album: "Jugband Blues," which is as disjointed as a listener can imagine, with a Salvation Army blowing in from nowhere to lead into the tune's final lyrical section. It ends with these words: "What exactly is a joke?"

By mid-1970, Syd Barrett had pretty much disappeared from the music scene, and few people outside his immediate family saw much of him during the last three-and-a-half decades of his life.

But his former bandmates never forgot him. The highly successful "Wish You Were Here" is a song cycle that tells of his abrupt rise and fall, particularly the title track. And the character of "Pink" in Waters' rock opera "The Wall" seems to be very close to Barrett.

To the best of anyone's knowledge, he never complained about how he was portrayed - if, indeed, he was aware of the portrayal.