LAFAYETTE, Calif. — Brent Mydland, keyboard player for the Grateful Dead, one of the most enduring of rock bands, died Thursday at his home, the band's publicist said. He was 38.

It was not known how Mydland died, but he was pronounced dead at his Contra Costa County home northeast of San Francisco shortly after 10:30 a.m., authorities said.

"We don't really know how Brent died and, as of now, we believe it was an accidental death," said Dennis McNally, longtime publicist for the band. "All I can say is that we lost a brother and it hurts a lot and we're going to miss him a lot."

An autopsy was scheduled for today, Contra Costa coroner's officials said.

The band had returned to its home base in the San Francisco Bay Area on Tuesday after touring the Northwest, Midwest and South.

Mydland was the third keyboardist to play for the popular band who has died. Founding member Ron (Pigpen) McKernan died of liver disease in 1973, and Keith Godchaux died in a car crash in 1980, one year after leaving the band.

Mydland, who joined the group in 1979, had played an increasingly larger role in the band, writing and performing as lead singer for three songs on the band's latest album, "Built to Last."

As the newest member of a band that has toured regularly since 1965, it took years for Mydland to step out of the shadows of the rhythm section and backup vocals to take a more assertive role in the Grateful Dead's unique brand of improvisational rock 'n' roll.

But as Mydland found his way through the dense and jazz-like jams that are the band's stock and trade, he proved himself a forceful player equally adept at gentle ballads, stinging blues standards and straight-ahead rock.

He was not content with occasional solos and after learning to plow his piano and organ into extended jams, started taking center stage with his bluesy, wailing voice. On some of his own songs, such as "Blow Away," Mydland would sometimes abandon his playing, using his keyboards only to keep his balance as he leaned into the microphone to belt out improvised lyrics, chants and wails.

Born in the heyday of the psychedelic era of the 1960s in San Francisco, the Grateful Dead quickly became popular for its anti-commercial stance. Although never producing a major hit single, the band has recorded numerous albums.

Building an underground reputation by playing regularly and often for free in its early existence, its outdoor concerts became legendary for attracting tens of thousands of fans--known as Deadheads--across the country. The fans would think nothing of camping out for days just to get a glimpse of the band.

"It's the end of an era," said Emily Hansen, a 22-year-old San Francisco resident who said she has seen the band more than 100 times. "I just faxed them a sympathy letter."

As of Thursday, a series of concerts scheduled to begin Aug. 31 at Shoreline Amphitheater in Mountain View, Calif., has not been canceled, McNally said.

Mydland is survived by his wife, Lisa, and his daughters, Jessica and Jennifer.

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