listening to jewish music is very bidieved because after the beis hamikdash it became assur to have music due to the fact that we are supposed to be mourning for the churban. I have heard myself from poskim that optimally one should not listen to Jewish music. As Sam2 said you will be hard pressed to find clear mekoros about non-jewish music (and no shirei agavim is not referring to stam non-jewish music). So interestingly enough there is more of a mekor to assur jewish music than non-jewish music. That being said I am not suggesting that one should start listening to non-jewish music.
