Brawl Stage Manager is a program that uses BrawlLib to help you see and organize the stages, module files, and stage portraits that are installed on your SD card (or in whatever folder, on whatever device, you use for Brawl hacks.) It can also change certain PAT0 entries (through a special dialog.)
This program uses collapsible splitters to allow you to hide certain parts of the window. If you want the music panel to stay hidden, though, you should uncheck "load .brstms" in the Options menu.
See the readme file (BrawlStageManager.txt) for more information and recent changes.