Alexander "Skip" Spence, the troubled former singer/guitarist for '60s psychedelic folk-rock band Moby Grape, died in a Northern California hospital Friday. He was 53.

Spence was the original drummer for legendary '60s San Francisco rock group the Jefferson Airplane and wrote a number of songs that appeared on their early albums, including "Blues From an Airplane" and "My Best Friend."

"He was a full-blown Aries," said Moby Grape guitarist Jerry Miller. "If he saw something he wanted, he'd just go for it, no reserve. He never thought, 'this might not be the best thing' or 'I should be careful.' If he saw something that looked good to him, he was, boom, right on it."

The musician entered the hospital April 7, suffering from pneumonia. Reprise Records publicist Bill Bentley said Spence eventually succumbed to the illness, along with complications from lung cancer.

"I saw him last week," said Bentley, who produced a Spence tribute album due in June. The album is set to feature covers of songs from Spence's first and only solo album, Oar, by such artists as Led Zeppelin singer Robert Plant, Beck, Tom Waits, Mudhoney and Afghan Whigs singer Greg Dulli.

"He was a free spirit, and he was not meant to be anything but. They had him on a ventilator and every time he regained consciousness he tried to pull the tubes out. He knew he couldn't breath without it, but he wanted it out."

Spence, who would have turned 54 Sunday was considered a gifted singer/songwriter and guitarist who wrote some of Moby Grape's best material, including "Omaha." He wrote and performed every note on his 1969 solo debut, Oar, including the lead track "Little Hands" (RealAudio excerpt). The album is now considered an underground treasure for its mix of blues, gospel and eccentric psychedelic touches.

Spence's musical career began in 1965 when he was asked by Jefferson Airplane singer Marty Balin to join his new band. Spence became the psychedelic rock group's drummer despite his not knowing how to play the instrument.

After the release of Jefferson Airplane's debut, 1966's Jefferson Airplane Takes Off, Spence quit the group and formed Moby Grape with Miller and guitarist Peter Lewis; the band also featured bassist Bob Mosley. Influenced by both American folk music and the British Invasion sounds of the Beatles and Rolling Stones, the band was quickly signed to Columbia Records. The group was praised during the mid-'60s for the flowing interplay between the three guitarists, and for their soulful harmonies.

Unfortunately, Columbia Records chose a gimmick to draw attention to the debut: five singles with 10 of the album's 12 songs were released simultaneously. The hype backfired; the album didn't sell and the band never recovered.

Spence quit Moby Grape in 1968. He was becoming emotionally unbalanced. In one notorious incident, Spence had a breakdown in a recording studio and ran through the studio waving a fire ax. That landed him in New York's Bellevue mental hospital. It was during his stay in Bellevue that Spence wrote the songs for his solo album, Oar, according to Bentley.

He was diagnosed as paranoid schizophrenic shortly before Oar's release and spent most of the next two decades in and out of institutions.

Spence was remembered by Miller as an unchained spirit. "He was the best rhythm guitar player in rock 'n' roll that I ever met," said Miller, who, ironically, was filming a "Where Are They Now?" segment for an upcoming VH1 special on Moby Grape when he heard Spence was dying.

Miller praised Spence for his deft playing on such Grape songs as "8:05" (RealAudio excerpt) and "Rounder," which he said he submitted to Spence and drummer Don Stevenson. He said the song came back to him in a fashion that "completely blew my mind. I had this little lead part on it and I gave it to him and he played all these high doubling parts on it that made what I gave him a skeleton of its former self."

Miller blamed hard drugs for contributing to the downward spiral Spence went into following Oar's release. Spence spent the final years of his life living on government assistance in a mobile home near Santa Cruz, Calif., with his girlfriend.

Bentley, who never spoke to Spence in person and who regretted that Spence was sick the one occasion he'd seen Moby Grape in 1968, said he'd remember the singer/guitarist for the "total freedom of his music and his personality. I've seen videos of Moby Grape and Skip was the guy who looked like he was plugged into the wall," Bentley said as "Omaha" blasted in the background.

"Certain people in rock 'n' roll have that thing and he had it. By the time he made Oar, it was a total expression of one guy's personality and spirit. It's kind of limitless, which is what he was to me. He had no limits."

The Spence tribute album, More Oar: A Tribute to Alexander "Skip" Spence is set to be released in late spring, according to Bentley. The album, intended to raise money for Spence and his family, also features covers by Screaming Trees singer Mark Lanegan, Son Volt singer Jay Farrar, Robyn Hitchcock, the Ophelias, Flying Saucer Attack and The Minus 5, featuring R.E.M. guitarist Peter Buck.

R.E.M. singer Michael Stipe sang lead vocals on drummer Aton Fier's all-star combo the Golden Palaminos' cover of "Omaha."

In what Bentley said was unintentional timing, Sundazed Records will issue an album titled The Complete Oar Sessions, which compiles the original, out-of-print album, as well as five bonus tracks.

(Contributing Editor Teri vanHorn contributed to this report.)