Board Thread:Support Requests - Getting Technical/@comment-37102663-20190118221141/@comment-34888194-20190118222203

This is not recommended, as suggested by Sannse. Sannse said:

I strongly recommend not doing that. Autoplay music is generally not welcomed by visitors, especially if they are already playing their own music. It's much better to have a control to allow people to turn it on and off themselves.

There's more about adding .ogg clips at Help:Audio (we don't support .mp3s). Or you can ask on the Forum for help from other users.