Hello and tanks for reading this Tutorial
Set your own background music for GMOD:
1. Open your Garry's Mod folder and go to "sound"
2. Now create a folder and give it the name ''ui''
3. You need an .mp3 file(any song or music).
4. Change the name of the .mp3 file to ''gamestartup01''
5. Put the gamestartup01.mp3 file in your garrysmod/sound/ui folder
6. Done!!! Very easy isn't it
Info's about background music in GMOD:
background music is cool but sometimes it lags your gmod and it need more time to start it.
you mustn't upload music of groups, bands.... (Ex: Linkin park). Uploading music without
a license is illegal! but you can use music of other bands for yourself.
You shouldn't use background music if your PC is very laggy!
oh and for CSS the same thing but without 01