Maniaplanet Forum

Is there a way to turn off custom music download?

Currently not. But it would be something to add to the P2P configuration options: do not upload / download music.
The only thing you can do actually is to disable music change during races (Audio options).

And that doesn't apply to custom songs because they just loop.
I agree it would be nice to turn off custom music downloads so that you could listen to the default songs if you, say, don't really like the genre the server jukebox uses.