As heard in IRATE Gamer's video interview of Sonic 4, I noticed a familiar favorite tune playing in the background of this clip. None other than Hydrocity Zone ...more over like the Act 2 iteration, fully arranged with guitars (doesn't like like Jun Senoue, either...)!

http://www.youtube.com/watch?v=HGu-FnVUVbo

I'm hoping this isn't some OCRemix or doujin because it's about time for some official arranges from classic Sonic games...

THOUGHTS!!

My guess is that the background tune in that video is probably not from Sonic 4. You could always ask Irate Gamer though, he'd probably let you know.

It seems like a remix, I dont think Sonic 4 Episode 1 will have a Hydrocity arrangement as the whole OST is being done by Jon Senoue with classic Genesis sounds and this remix is more rock.