Although often uncredited, Ned Lagin played keyboards at a number of the Grateful Dead's live shows between 1970 and 1975. His playing was especially prominent during the Summer and Fall, 1974 tours, when his synthesizer work was allocated its own set between the Grateful Dead's first and second sets. He also appears on the album "American Beauty".

He released an album entitled "Seastones - Ned Lagin and Phil Lesh" (Round RX 106), in October, 1975, which was recorded in SQ-Quad. The album was re-released in stereo on CD as "Seastones - Ned Lagin" (Rykodisc RCD 40193) in January, 1991. The CD includes the original nine section "Sea Stones" (42:34) from February, 1975, and a live, previously unreleased, six section version (31:05) from December, 1975.