StageBgmInfo is a BCSV table that defines the music to play when a music change occurs in-stage, for example when entering a warp pipe. The file can be found in SMG2 in AudioRes/Info/StageBgmInfo.arc/root/StageBgmInfo.bcsv. It contains the following fields:
|StageName||STRING_OFFSET||The internal galaxy name, for example RedBlueExGalaxy.|
|ChangeBgmIdName0 .. 4||STRING_OFFSET||ID name of the music, for example MBGM_SMG2_GALAXY_01.|
|ChangeBgmState0 .. 4||LONG||Unknown.|
Make sure that ScenarioBgmInfo also contains an entry for your galaxy. Editing only one of these files will crash the game!