The liner notes for Images And Words contain the following Thank You’s.
“All of our friends in the following bands: Meanstreak, Fatez Warning (Jus’ Kiddin’!!), Crumbsuckers/Heavy Rain/Pro-pain, Watchtower, Hittman, Mystery Play, Skitzo, Monolith, Enforce, Primo, Bruce Dickinson, Marillion & Crew, Winger & Crew, Zebra & Crew.”
Meanstreak was an all-girl thrash metal band founded in 1985 by guitarists Rena Sands and Marlene Apuzzo. On bass was Lisa Diane Pace, Yael Devan was on drums and Bettina France on vocals. They released an album called Roadkill in 1988, and opened for several famous thrash metal bands like Flotsam and Jetsam, Anthrax and Overkill. Mike Portnoy became good friends with the drummer, and during a trip to LA for the Foundations Forum Music Convention, he and John Petrucci ended up hanging with the drummer and the two guitarists. After a few days, John Petrucci hooked up with Rena Sands, and a short while later Mike Portnoy hooked up with Marlene Apuzzo. These would turn out to be relationships lasting to this day. Some years later, John Myung would also end up getting together up with Lisa Martens Pace. The band didn’t last, and broke up finally in 1994, with Rena and Marlene both becoming more or less full time housewives (although you’ll often find Rena out playing local shows in the New York area).
Fates Warning was a band that early on became friends with Dream Theater, even thanking them on their own album “Parallels”. But the thank you was misspelled as “Dream Theatre”, and thus the on purpose misspelling of “Fates Warning” in the thank you for IAW.
Crumbsuckers was a NY thrash punk/metal band that crossed paths with DT at many concerts in the NY area. They changed vocalist and became Heavy Rain in 1989, but disbanded in 1990. From there, several members started the band Pro-pain. Mike Portnoy stated that the members of Crumbsuckers were responsible for landing DT its first record deal with Mechanic in 1988.
Watchtower is a progressive metal band with Ron Jarzombek as the most well-known member.
Marillion had brought on Dream Theater for their New York Ritz concert in November 1989 as a support act, which incidentally would be Charlie Dominici’s last show with Dream Theater. DT would also open for Marillion at Sundance in Bay Shore, Long Island in june of 1990. This is infamous for having Steve Stone as the vocalist, where he constantly shouted “Scream for me Long Beach”, which would’ve been great had they actually been playing at Long Beach. These were some of the biggest shows for DT at that point in time. The friendship with Marillion continued, with Steve Rothery and Steve Hogarth both appearing at the Dream Theater Uncovered gig at Ronnie Scott’s.
Dream Theater also opened for Winger in february of 1989. Zebra was also a band Dream Theater opened for (and later would feature a cover song of on Black Clouds & Silver Linings bonus disc).
The rest of the bands are various local thrash metal bands that were commonly seen in the same circles as Dream Theater in the early days.