Original sentence: After their fall tour of 1989, Bill Spooner left the band, followed by Vince Welnick in 1990 who then joined the Grateful Dead that same year.Later, Gary Cambra joined on keyboards and guitar
Edited sentence: After their fall tour of 1988, Bill Spooner left the band.Gary Cambra, who had previously been filling in for Vince,  then joined on keyboards and guitar in 1989.Vince Welnick took to the road with Todd Rundgren in 89,  who then joined the Grateful Dead in 1990