I was feeling a bit nostalgic and decided to play a game or two of the old Starcraft Broodwar. I don't like in-game music much so I tried to find a way to turn off the background music. After scouring the internet, no one had an answer. I guessed a few things and tried CTRL S. It turned off the sound effects but not the music. Going off of my latest guess, I tried CTRL-M which turned the background music off. Thought I would post this here to help some of you all with the same issue. GL!
Turn off in-game sounds:
Turn off in-game music: