Jefferson Airplane’s founding guitarist and singer Paul Kantner died Thursday of multiple organ failure and septic shock. He was 74. The San Francisco Chronicle reported that he had a heart attack earlier in the week. Kantner had been in poor health in recent years and suffered a heart attack last March, according to the Chronicle. In 1965, he formed Jefferson Airplane and scored hits such as “Somebody to Love” and “White Rabbit.” Five of the band’s seven albums went gold. Kantner recorded a solo album, Blows Against the Empire, with Jefferson Airplane singer Grace Slick in the early 1970s to begin the formation of his second band, Jefferson Starship, which went on to score platinum and gold records. Kantner left the group in 1984, but rejoined in 1992 and continued to play with them until his death.