I mentioned this a little bit
on a post on another thread years ago (although the YouTube links I posted are taken down now...), but I'm under the very strong impression that the version-exclusive "secret records" (
"Waves",
"Modest Decor",
"Shedded Fur", and
"Giant Socks") were composed by sound director Ryoji Yoshitomi instead of Hajime Wakai, as most of them make use of similar instrumentation from the GBA titles Wario Land 4 / WarioWare Inc. that Yoshitomi did work on (maybe most noticeable on "Giant Socks"). As a matter of fact, there are sections of "Waves" that sounds very reminiscent of WarioWare Inc.'s staff roll music.
Apparently all of them have a "weird" placeholder instrument sample that gets replaced with actual voice recordings via the DS microphone through the in-game "White Record", but I haven't played nintendogs in many years so I can't really verify it on my own.