NEW YORK — Paul Kantner, the singer, guitarist and songwriter who co-founded the pioneering San Francisco psychedelic rock band Jefferson Airplane and its spin-off group Jefferson Starship, died Thursday at the age of 74, his manager told to ABC News.

Longtime Jefferson Starship publicist Cynthia Bowman told the San Francisco Gate that the cause of death was multiple organ failure. Kantner had suffered a heart attack this week, according to the newspaper.

Kantner formed Jefferson Airplane in 1965 with his friend, singer Marty Balin, and the band’s initial lineup also included singer Signe Anderson, guitarist Jorma Kaukonen, bassist Jack Casady and drummer Skip Spence. After releasing its debut album, “Jefferson Airplane Takes Off,” in 1965, singer Grace Slick was brought in to replace Anderson and Spencer Dryden took over for Spence. This lineup of the group went on to record the group’s landmark 1967 record, “Surrealistic Pillow,” which featured the band’s only top 10 hits — “Somebody to Love” and “White Rabbit.”

Kantner contributed his voice and guitar to many of the group’s songs, and wrote or co-wrote such tunes as “Today,” “Martha,” “Crown of Creation,” “We Can Be Together” and “Volunteers.” He also co-wrote “Wooden Ships” with David Crosby and Stephen Stills, a song recorded by both Airplane and Crosby, Stills & Nash. In 1971, Kantner fathered a daughter with Slick named China.

After Jefferson Airplane broke up in 1972, Kantner formed a new group with Slick called the Jefferson Starship, which Balin eventually joined. That group released a series of pop and rock hits throughout the 1970s and into the ’80s. Kantner exited the band in the mid-80s over the artistic direction of the group, and then formed the short-lived KBC Band with Balin and Casady.

Jefferson Airplane reunited in 1989 for a new album and tour, and a few years later Kantner re-formed Jefferson Starship with a shifting lineup of musicians that included Balin, Casady and founding Jefferson Starship bassist David Freiberg. In 1996, Kantner was inducted into the Rock and Roll Hall of Fame as a member of Jefferson Airplane.

In March of 2015, Kantner suffered a heart attack, but he returned to Jefferson Starship after a period of recovery and continued to perform with the band until his death.

He is survived by his daughter and two sons.