oh god, I remember the idea of rating Square soundtracks track by track. Man, has it really been that long....?
digging through that link, and double-confirming with this (via machine translation), as well as a few youtube videos... (I'm bored)
12) Thirteenth Struggle
-First of two type of boss themes for battles with Organization members. Comes from the boss theme of the same usage from Chain of Memories
22) Laughter and Merriment
-Cutscene theme for certain cutesy scenes, like when YuRiPa appears
23) Desire for the Lost
-Regular boss theme for first half or so of the game. Examples given: Hydra, the elemental Lords in Agrabah
33) Dance to the Death
-Mid-boss theme for first half of the game. Examples given: Past Pete, several of the larger battles in the Land of Dragons
38) Vim and Vigor
-Regular boss theme for first half of the game. Examples given: Barbossa, Shan Yu
-Gummi ship theme used for "Phantom Storm" and "Sunlight Storm" stages
44) Rowdy Rumble
-Mid-boss theme for first half of the game. Examples given: Hyenas, protecting Queen Minnie in Disney Castle
49) Floating in Bliss
-Gummi ship theme used for "Splash Island" and "Floating Island"
01) Isn't It Lovely?
-Opening theme of Atlantica
02) Let's Sing and Dance!
-Plays when practicing the Atlantica gameplay
-Regular boss theme for second half of the game. Examples given: Grim Reaper, Test Subject, Hostile Program, Storm Rider
11) Hazardous Highway
-Gummi ship theme used for "Broken Highway" and "Ancient Highway"
-Regular boss theme for second half of the game. Examples given: second battle with Hades, MCP, Oogie Boogie, Scar, Jafar
21) Sinister Shadows
-Mid-boss battle for second half of the game. Examples given: Sark, the thousand Heartless battle
22) Thirteenth Dilemma
-Second of the two themes for battles with Organization members
25) Battleship Courage
-Gummi ship theme for "Assault of the Dreadnought"
-Cutscene music for various heroic events, like when Hercules fights the Hydra
37) Dark Horizons
-Music to the secret movie gained by completing Jimmy's Journal in normal or clearing all worlds in Proud. It's basically just a small preview of the "birth by sleep" movie at the end of KH2 Final Mix+
there were a few extra examples given on the Japanese page, but I simply wasn't able to understand them.
man, KH2 has a lot of battle themes. Let's see...
about fifteen regular battle themes, seven normal boss themes, three special boss themes, and three last boss themes. Aaaaaand I didn't even have to count, because yeah, the liner notes (garbled as the translation is) confirms 28 boss themes. Still not as many as Bushi Seiryuuden or Mother 3, but I think that's the third-most I've seen in a non-strategy RPG.
And, come to think of it, Final Mix+ adds two battle themes and two boss themes, so that bumps it to 32, outstripping Bushi Seiryuuden. And there was even a new final boss them for RE: Chain of Memories. Geez.
Also, Wikipedia just told me that the KH2 discs from the KH Complete Box actually featured some more tracks. That would probably explain the tracks from the PSF2 set that I couldn't place....