WIY- He might not be prophet(especially since we don’t have prophecy now a days)but why would the fact that he is a non-Jew invalidate the spiritually uplifting music he has created?
Why is it the consensus that it is better to listen to a shwekey song that carries no meaning for you than to listen to a song by Josh Groban or Simon & Garfunkel that spiritually uplifts you. Isn’t the point of music to bring you closer to G-d? Why would someone being non-Jewish or non-religious impact the force their music can have on you?