RatDog went through a series of personnel changes from 1995 and 2000. Former Grateful Dead keyboardist Vince Welnick performed with the group in late 1995. Former Chuck Berry collaborator Johnnie Johnson performed with the group from February 1996 to May 1997 and was then replaced by Jeff Chimenti who has been with the band ever since. Keyboardist Mookie Siegel also played with the band between 1996 and 1997. Saxophonist Dave Ellis was a member of the group from 1996 until 1999 when he was replaced by Kenny Brooks in 2000 until his departure in 2012. Mark Karan joined on guitar in 1998 until his departure in 2012. Original stand up bassist Rob Wasserman was replaced by bass guitarist Robin Sylvester in 2003. Wasserman rejoined the band in January 2012 and played alongside Sylvester until the former's death in June 2016. The lineup of Bob Weir (rhythm guitar, lead vocals), Jay Lane (drums, vocals), Jeff Chimenti (keyboards, vocals), Kenny Brooks (saxophone, vocals), Mark Karan (lead guitar, vocals) and Robin Sylvester (bass guitar, vocals) was the longest serving lineup of the band. They performed together for nine years from 2003 until 2012, with the exception of 2007 when Karan was replaced briefly by Steve Kimock to battle a health problem.