MSU-1 allows for the use of custom in-game music. It works on original hardware, the SuperNT, and certain emulators. This guide will explain how to find custom music packages, often called MSU packs, and how to configure them for use with original hardware, the SuperNT, and the snes9x emulator.
MSU packs contain many files, most of which are the music files which will be used when playing the game. These files should be named similarly, with a hyphenated number at the end, and with a `.pcm` extension. It does not matter what each music file is named, so long as they all follow the same pattern. The most popular filename you will find is `alttp_msu-X.pcm`, where X is replaced by a number.
There is one other type of file you should find inside an MSU pack's folder. This file indicates to the hardware or to the emulator that MSU should be enabled for this game. This file should be named similarly to the other files in the folder, but will have a `.msu` extension and be 0 KB in size.
Many MSU packs use copyrighted music which is not permitted for use on platforms like Twitch and YouTube. If you choose to stream music from an MSU pack, please ensure you have permission to do so. If you stream music which has not been licensed to you, or licensed for use in a stream in general, your VOD may be muted. In the worst case, you may receive a DMCA take-down notice. Please be careful to only stream music for which you have the rights to do so.