Does not one seriously have an answer to this? I just want to set up a music list like in normal campaign or melee games, otherwise my custom music just repeats and gets repetetive after awhile.
Vexorian has a solution for this in his open source hero arena map which he released some time ago on wc3campaigns.net. Search in the trigger section(I think it is there). His method is toring n sound datas to 1 string array and play them randomly. It works perfectly, I myself use it.