The Pokemon Company just released the Diamond / Pearl soundtrack for free on https://soundlibrary.pokemon.co.jp/download (fairly certain if you’re not in Japan or use a japanese VPN at this time you will get a 403 error), and I figured I would add it. However I can’t figure out what artist or label to add this under as its never listed on the site, and the download is just .wav’s without any tags. Furthermore the downloads are “Disc 1” and “Disc 2” (in japanese) but the tracklist doesn’t mention any discs and is just tracks 1 through 149.
VGMDB has a few diamond/pearl releases, with good artist credits on some, so you should be able to use those?
When in doubt you can set the artist to [unknown] and come back later, or let the community sort it later!
Label is probably [no label], you can always add the company that’s running the website if you feel like it’s acting enough like a ‘label’.
You will need to figure out if the audio is identical to https://beta.musicbrainz.org/release/337cd6a2-c0da-421f-84f7-045e7accee22 or different. If it’s the same, just clone the release. If it’s not, you will want to use new recordings.