Paul Kantner, one of the founding members of Jefferson Airplane, died on Thursday of multiple organ failure.
The guitarist and vocalist had suffered a heart attack earlier this week.
His death was confirmed by his longtime publicist and friend, Cynthia Bowman, who said he died of multiple organ failure and septic shock, according to SF Gate.
Kantner suffered from numerous health problems over the years and had an earlier heart attack in March 2015. In October 1980, he was taken to Cedars-Sinai Medical Center in Los Angeles in serious condition from a cerebral hemorrhage at age 39, but he made what was considered to be a remarkable recovery.
Kantner formed Jefferson Airplane in 1965 with singer Marty Balin in a San Francisco folk bar called the Drinking Gourd.
The band — later also including Grace Slick, Jorma Kaukonen, Spencer Dryden and Jack Casady — performed at the original Woodstock festival and became synonymous with the LSD-spiked 1960s era as the flower power generation took over San Francisco.
Their hit “Somebody to Love” and “White Rabbit” are both among Rolling Stone’s “500 Greatest Songs of All Time.”
The group broke up in 1972 and essentially split into the two bands Hot Tuna and Jefferson Starship.
Kantner would end up being the only member to appear on all Jefferson Airplane and Jefferson Starship albums, and his songwriting became known for its whimsical or political lyrics with a science-fiction or fantasy theme, usually set to music that had a hard-rock sound.
He continued to record and tour during his latter years and joined the band to celebrate the 50th anniversary of Jefferson Airplane with special shows that also featured Grateful Dead tribute group Jazz Is Dead.
Kantner is survived by three children: sons Gareth and Alexander and daughter China.