"A Child Is Coming" - Blows Against the Empire - Paul Kantner/Grace Slick/"Jefferson Starship" (really, The Planet Earth Rock and Roll Orchestra, or PERRO) - at about 1:27, Jack Casady’s bass becomes the lead, then the solo instrument.
"Laughing" - If I Could Only Remember My Name - David Crosby/PERRO - Phil Lesh on bass, all the way through.
Both albums were recorded at the same time in the same studio in San Francisco. PERRO is a group of musicians drawn from the Jefferson Airplane, The Grateful Dead, Quicksilver Messenger Service, CSNY, Santana, and including Laura Allan and Joni Mitchell.