Signe Toly was born in Seattle, Washington and raised in Portland, Oregon. After traveling to San Francisco, she joined Jefferson Airplane in 1965 and soon married Jerry Anderson, a member of the Merry Pranksters, a group of people who lived communally and had taken a road trip across the United States in 1964. She became pregnant, and after giving birth, decided to leave the band and return to Oregon. She would later divorce Anderson, survive a battle with cancer, sing with the band Carl Smith and the Natural Gas Company, remarry, and occasionally perform as a guest with some later incarnations of Kantner's band Jefferson Starship.
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On JATO, Anderson mainly sang harmony vocals, but sang lead on the Lester Melrose song Chauffeur Blues. Shown on the thumbnail, which reproduces the album's cover, are (L-R) Marty Balin (vocals, guitar), Jorma Kaukonen (lead guitar), Signe Anderson (vocals), Paul Kantner (guitar, vocals), Skip Spence (drums), and Jack Casady (bass).
The song High Flying Bird, by Billy Edd Wheeler, was recorded around the same time as JATO, but left off that album. It was later included in the compilation album Early Flight. On the following live version, Balin, Kantner and Anderson, in that order, sing the lead vocal on the three verses. Both Anderson and Spence left Jefferson Airplane after JATO was released, but Spence's departure and replacement by Spencer Dryden occurred before Anderson left the band. It is therefore possible but uncertain that Dryden might be playing drums for this performance.
Anderson's last performance as a member of Jefferson Airplane occurred on October 15, 1966. On the next night, they appeared for the first time with Grace Slick, thus debuting what would be called their classic lineup.
UPDATE: The YouTube channel Rock History Music posted this video on Anderson's passing: