Signe Anderson, the first lead singer for the San Francisco-based Jefferson Airplane psychedelic rock band before Grace Slick, died on January 28, 2016 at age 74, the same day as Paul Kantner, also 74, according to this short article at The Rock Poster Society:
Signe left the Airplane when she got pregnant and was replaced by Grace Slick who brought a number of Great Society songs with her when she joined Jefferson Airplane.
Paul Kantner played a few years ago at the Royal Theatre with the Jefferson Starship band from San Francisco.
Tragically, Paul Kantner was drunk and obnoxious that night and on the whole, he put on a disgraceful performance in Victoria.
I felt ripped off, frankly, but I still love Jefferson Airplane, especially Jorma, Marty, Grace and Surrealistic Pillow, one of their earliest LPs.