Paul Kantner, an innovative guitarist and songwriter instrumental in being at the forefront of the San Francisco sound of the late 1960s with Jefferson Airplane, died yesterday of multiple organ failure and septic shock. He was 74.

The news was confirmed by the late musician’s ex girlfriend and publicist, according to the BBC, which added that Kantner had suffered a heart attack several days earlier.

The San Francisco native co-founded the psychedelic rock outfit best remembered for classic songs like “Somebody to Love” and “White Rabbit,” sung by the dynamic Grace Slick. Jefferson Airplane, with Kantner, frontwoman Slick, frontman Marty Balin, and masterful guitarist Yorma Kaukonen, was part of a musical brotherhood that also included bands like The Grateful Dead and others and had a musical swagger that spoke about sex, freedom, rebellion, and the anti-establishment. Airplane records like Surrealistic Pillow and Crown of Creation still stand as benchmarks in the genre of the times, classic records which perfectly capture the zeitgeist.