Normally, the sdat file plays the 1st 15 seconds over and over but with some hex editing, I managed to unlock the rest of the music!

Also, the unused channels (5 & 8) are even more mysterious than with Bath Time. There's not a single note in those channels but the instruments are still set, 5 being a ride cymbal and 8 being a tambourine.
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Game : Nintendogs
Console : Nintendo DS
Release Year : 2005
Composer : Hajime Wakai
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BPM : 120

Timestamps :
0:00 [Channel 2 ; 3 ; 9 - 14]
2:07 [Channel 3 ; 6 ; 9 ; 12 ; 14]
3:50 [Channel 1 ; 3 ; 7 ; 9]
5:32 [Normal: 1 - 3 ; 7 - 14]
7:16 [Excrement: 1 - 4 ; 7 - 14]
8:59 [Garbage: 1 - 3 ; 6 - 14]
10:42 [All Variants combined]
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HxD : https://mh-nexus.de/en/hxd/
VG Music Studio download : https://github.com/Kermalis/VGMusicSt...
Corrscope download : https://github.com/corrscope/corrscope