Remember that gen 1/3 (Red/Blue, Firered/LeafGreen) has a different arrangement for many recurring themes, compared to gen2/4 (Gold/Silver, HeartGold/SoulSilver). It's not just made first for gen 1; then touched up in gen 2, then taking advantage of GBA capabilities in gen 3 and finally DS sound in gen 4. HGSS might sound closer to FRLG because of the non-8-bit sound, but it's actually a remix of the gen 2 one. This is very noticeable in the wild battle theme, although in the trainer battle theme, the cool chromatic "bumblebee" sound from gen 2 was removed in gen 4, so it sounds closer to gen 1 and most of all, gen 3. Just a random sidenote.
My favourite versions then, of the Kanto trainer themes, are the GSC/HGSS versions of it. I do like Sinnoh's battle theme more though, so that gets my vote.
Edit: I think actually the bumblebee sound is still in the HGSS games as well, after putting my iphone into my ear. I'll have to listen to it with better equipment to really hear it. Never noticed it before.
Yep.
