Well, There was plenty of Music Changes from Alpha to E3 demo to Final.
Sea Sidehill
E3 Demo: Plain, Really dull to be honest, (Music Sample coming soon)
Alpha: Heavy bass from Alpha ADX, More same E3 Drums.
Final, Bass lowered, Differnet Louder Drums used.
Ocean Palace:
E3: Like a remix of Sea Side hill, But it was given louder drums and given to 2P Seaside hill and Sea Gate.
Alpha: A Dance type track, livly song. Same basic tune as used in final.
Final: Alot more of a Pop like song now, not as livly as the Alpha one but its much better in places.
Grand Metropolis:
E3: Not Featured.
Alpha: No big clash of drums and Gituar near the beginning, its like the normal tune was struggeling to get out to be honest.
Final: Alot more bass added, made abit more weird.
Power Plant:
E3: a mystirious track that seemed to come out of no where, basic Faster version of the Alpha track, no fancy intro though. Not a big change.
Alpha: Fancy intro sounding like Machining, Faster than the final track though.
Final: Slowed down Alpha version.
Casino Park:
E3: Not Featured
Alpha: Sounds a hell-of-a-lot more like a casino/party kind of track. I prefer this than the final one
Final: Sounds like a duller version of the Alpha track.
BINGO Highway:
E3: Not Featured.
Alpha: More or less not changed, A few SFX were changed and it seems this annoying high pitched scream like nosie was cut out of the final one too, and a bit more bass added in some parts, in some parts less.
Final: Changed SFX, no Annoying Scream SFX, More or less same bass all the way through.
Rail Canyon:
E3: Nice, Heavy rock music. Basic Seaside hill like drums.
Alpha: Added louder drums and extra beats. bass sounds like the E3 version. Quite Echo-y too.
Bullet Station:
E3: Not Featured
MK:DD Demo disc: Same as Alpha.
Alpha: Same as final, just some lower pitched chords from the gituar.
Final: Higher pitched Chords, a bit more of a bubblie feel too it.
Frog Forest:
E3: -Not Featured-
Alpha: Bass is freaky, Same as final. Gituar is... lower pitched. Tune is slower too. Loop in ADX is different to Final.
Final: Not so echo-y. Much more of a air-y feeling added, bass fixed.
Lost Jungle:
E3: -Not Featured-
Alpha: Non-looping huge track. Odd tune really, In this version there is a flute, and some kind of Clackers in the background.
final: Short looping track, no flute this time, whole tune is ripped apart and re-made with the same instruments. Shame really.
Hang Castle:
E3: -Not Featured-
Alpha: Much Faster track, much more livlier.
Final: Slower, Less livlier but better slowed down.
Hang Castle Upside down castle:
E3: -Not Featured-
Alpha: Screaming stuff dosn't come in untill abit further into the track, bit more tune to it.
Final: Shorter, Slower tune with alot more screaming and freaky noises
Egg Fleet:
E3: -Not Featured-
Alpha: Alot of bass in absence of abuance sound.
Final: Abiance tune to it, less bass.
Final Fortress:
E3: -Not Featured-
Alpha: Once again missing basic Ambiance sound.
Final: With Basic Ambiance sound.
--Bosses--
Egg Hawk:
Alpha: Clear of the intro digging into the tune itself
final: Not much changed, a new Echo Effect added though.
Team Face of the first:
Alpha: Plays what would play facing Team Dark with Team Sonic.
Final: Full of freaky drums, and a Grand Metropolis style intro.
Robot Carnival:
Alpha: I'm not sure the Alpha has one,
Final: Normal.
Egg Albotross:
Alpha: A stringy track, everything but the intro and looping is the same.
Final: Normal.
Team face of the second:
Unless you're facing Team Dark it will seem weird becuase its the Team Dark theme again.
Robot Storm:
Alpha: Like Robot Carnival Scince the game in the final uses the same track, This wouldn't have a song playing ether.
final: Normal.
Egg Emporer:
Alpha: Dull track, Alot of bass missing.
Final: Same but added Bass and it seems alot clearer. Could be the quality of the ADX.
Metal Madness:
Alpha: Really Orcastrated nothing more than that.
Final: Like Alpha just has this robotic sound in it.
Metal Overlord: (What I'm Made Of)
Alpha: Well, it consists of "Try to reach inside of me, try to drain my enegy, Let me show you just what I'm made of". Twice, with a "Now" on the end of the second one.
Final: Full Song, definatly suits the boss battle.