Paul Kantner, founding member, guitarist and singer for Jefferson Airplane and Starship, died Thursday of multiple organ failure and septic shock.br He had suffered a heart attack earlier in the week, according to San Francisco Chronicle.br He was 74.br The musician had been in ill health in recent years, with Kantner suffering a heart attack in March 2015, according to the paper.br Verging on a breakup in the early Seventies, Kantner recorded a solo album, Blows Against the Empire , with Jefferson Airplane singer Grace Slick, crediting it to Paul Kantner and Jefferson Starship.