Paul Kantner, co-founder of the Jefferson Airplane and a pioneer of the San Francisco music scene in the 1960s, died Jan. 28 at the age of 74. He had suffered a heart attack earlier in the week, according to his longtime publicist and friend, Cynthia Bowman. As singer, rhythm guitarist and song-writer as well as political visionary, Kantner guided the band from its folk-rock origins through its period as a pre-eminent symbol of the counterculture and youth rebellion, climaxing with the Monterey Pop festival that kicked off the 1967 "Summer of Love," its classic early-morning performance at the utopian-spirited Woodstock festival in August 1969—and that December's disastrous and violence-plagued Altamont Speedway free concert. The band had a rebirth in the 1970s, with a new line-up and more radio-friendly sound, as the Jefferson Starship, including fellow Airplane hold-overs Marty Balin and Grace Slick, Kantner's flamboyant and contentious lover. He continued to perform with various outfits in later years, including a re-formed version of the Starship and a briefly reunited Airplane in 1989. Kantner and his Airplane bandmates were inducted into the Rock and Roll Hall of Fame in 1996. He continued to be a vocal advocate for political causes, from cannabis legalization to support for the Nicaraguan revolution during the 1980s.