I apologize if I have jumped to conclusions. Whats wrong with most non Jewish music is not the fact that it is composed by a non Jew. It is the essence of the music. For example there is absolutely nothing wrong with classical music most agree. How is that possible? It was composed by a non Jew! The reason is because the music does not bring you down. It is like an art, just like a beautiful picture which can be beautiful no matter who paints it unless you paint something low and degrading. Its the same idea here. Sometimes non Jews can compose beautiful songs like an art with nothing wrong with them. But the majority of their music is made with degrading morals and dreadful intentions which brings the listener down. This quality that is so bad in most non Jewish music can hold true with a Jewish composer as well. If his intention is not to inspire but to be “cool” or to be modern or even degrading then it will come across in the melody regardless of the fact he is a Jew.
(By the way although I have said that not all non Jewish music brings you down it is not advisable to pick and choose since most of us dont understand what in essence is wrong with degrading music and it will almost always lead a person to listen to the bad as well as the harmless)
Hatzlacha