Because if Garry wants one I can compose one. Most Source games have some background sounds in the main menu, why shouldn’t GMod have some? I was thinking something maybe a comical theme song, something along the lines of early 20th century dixie, but a bit slower. I would use a tuba (for that funny bass), trombone(s), trumpet(s), a clarinet, maybe a piano, and drums.
I already have a ideas for a catchy song.