Pretty simple at all.
All you need to do is to take a music file (instrumental) and change the extension to .ogg
Rename it track1, and put it into the CGames\Toribash [Your Version]\data\music.
There you go!
I am actually listening to a tetris hard trance remix while playing toribash.
A little Hint: don't put too rock/metal songs, they rovine, destroy the game.
And they should be not too long, and something that loops.
EDIT: for example, to understand what i mean with "rovine, destroy", put in the folder a song from Jeff Beck, Scatterbrain, correctly name the file "Track1" and save it as a ogg vorbis.
EDIT2: some people have been asking me on how to change files to .ogg format. That's pretty simple, just search on the internet "Free Mp3 to Ogg converter". If you keep having trouble, well, i seriously don't know what to do. It worked for me by changing manually the extension: Right click on an icon->Rename->Call it track1.ogg

but how do u even change the format anyway? from mp3 to ogg

This should be more detailed,

Hidan try Not using a free set you found of google and put it in your Avatar. -rep
Also Try not double posting, Combine the posts.

I actully never knew that, Thank you I'm using it now

Don't work well.

Not enough details bud.

I'm just using it until Cyborgzx finishes the set that I've requested then I'll use that
-.-

You Should include how to change/convert it to the ogg. format

You're over complicating things.

Turn off the ingame music and load up a media player with all your playlists and stuff in it. Done.

Way to steal my tutorial... FAIL

You need a special programm and it's this. Hope it helps.

Just simply use a media player or a long epic song from YouTube (example, the drum n bass mix by Panda).