GB Sounds appears in 8 version groups since Generation IV, a Gameplay item in the Key Items pocket
PokéAPI item 484 of 2,223, Gameplay category, Key Items pocket
Effect, in PokéAPI's words
GB Sounds: “Use to listen to GameBoy era audio.”
Used by trainer outside of battle: Changes the background music to the equivalent 8-bit music.
Games
GB Sounds is listed in the text of 8 version groups, first in Generation IV
Game index by generation
IIIIIIIVVVIVIIVIIIIX
Named in
HeartGold and SoulSilverBlack and WhiteBlack 2 and White 2X and YSun and MoonUltra Sun and Ultra MoonLet's Go Pikachu and Let's Go EeveeSword and Shield