Yep. Usually I just use VGMdb
to find the composer listings, but those are off the soundtracks. The soundtrack for X and Y (be it iTunes or japanese copy) will have it I almost guarantee.
Although based on track record, it wouldn't be a horrible thought to assume that most battle themes were written by Junichi Masuda. Especially the most mainstream ones. (e.g. Wild Pokemon, Trainer, etc)
And if you really get skilled enough, you can tell who wrote a song by the style. That's right. The style. I've kinda learned to pick out Hitomi Sato's work. (Although tbh she's the composer who writes my least favorite songs from the Pokémon franchise for the most part)
From what I've noticed:
-Junichi Masuda's trademark seems to be lots of synths and strings. Often most battle themes and some other important pieces such as title themes, Pokémon Center themes, etc. Up till now, Junichi Masuda's been lead composer. But apparently Shota Kageyama's taken over that position. To which I say, "Great!". Shota Kageyama has been the one to consistently write my favorite pieces, and has contributed much. It would be pretty safe to assume that most songs were written by him. ("Most" meaning over 50%)
-Shota Kageyama's trademark seems to be all kinds of variety, but especially pieces with orthodox themes. Pieces/songs such as Champion Alder
, Ending -To Each Future-
, Route 10
, and Goodbye
-Hitomi Sato's trademark seems to be pieces without such a definite theme. Such pieces include Jubilife City (Day)
, and Wi-fi Connection
. Instrument choice seems to be generally lighter than those used by other composers. (Marimbas, electric pianos, etc)
-Minako Adachi, as far as I've seen, doesn't really do a whole lot. (At least by looking at past records) Never long or really mainstream pieces so far, and a lot of fanfares and such.
The trouble with recognizing a composer by choice of instrument, (or even by the suggestions above) is that now in X/Y the soundfonts have been revolutionized. Just remember, these are only "maybe"s. Double-check when the soundtracks come out.
Some composers Slow didn't mention appearing in the credits that have appeared in the past Pokémon games include:
-Go Ichinose - Been around since 2nd gen. I'm absolutely shocked that he's not in X/Y. What happened?
-Morikazu Aoki - Been around since 3rd gen. Although I'm surprised that he's not listed in X/Y, I don't remember him writing anything really memorable. Or a whole lot for that matter.
-Satoshi Nohara - Arrived with HeartGold/SoulSilver. Contributed with every Pokémon game since. Although I'm not surprised he's not in X/Y because he didn't seem to write much at all..
-Teruo Taniguchi - Only appeared in B/W2. Not with GameFreak. Not surprised he's not around anymore in the least.
-Takuto Kitsuta - Arranged a handful of songs in HeartGold/SoulSilver. No original compositions, nor has he seemed to contribute to any Pokémon game since. Not surprised he's not here.
I swear we had one, but I can't find it.
Were you by any chance thinking of this