I have to add to Just-a-guy’s question. What about music that was goyish but then the lyrics were changed to make it “Jewish”? Since there are several “kosher” artists who do that, it apparently has someone’s haskamah. In which case, I would argue it has nothing to do with the music – the problem would be the lyrics.
On the other hand, what about Mattisyahu (and I would argue that what he does is not music)? He recorded with a xian rock group. Is that music kosher or un-kosher?