Hornsby played more than 100 shows with the Grateful Dead from 1988 until Jerry Garcia's death in 1995. At some shows in 1988 and 1989, he joined the band as a special guest and played accordion or synthesizer. Starting in the fall of 1990, he played piano (and frequently accordion) at many gigs following the death of Grateful Dead keyboardist Brent Mydland, who died in July 1990. Mydland's place was filled in September 1990 by Vince Welnick, who became the sole keyboardist by March 1992, although Hornsby still sat in with the band on occasion.