Listening to music

Q: What types of songs are permissible to listen to?
A: There are three conditions which must be met in order to listen to music: kosher words, a kosher tune and a kosher singer:
1. Kosher Words – The Rambam explains in his commentary on the Mishnah (Pirkei Avot 1:17) that the words of a song need to be kosher. Anything which is forbidden to say is also forbidden to sing. If something is Lashon Ha-Ra, corrupt or immodest it does not become kosher because it is sung. It may even be worse when sung since when we speak, we say something and it is over, but when we sing, the song repeats and repeats. He says that the language of the song is unimportant: Hebrew or Arabic, or even English, the essence is that the words be kosher.
2. Kosher Tune – The Rambam mentions this factor in his letter to the Sages of Aram Zova (edition of Ha-Rav Yitzchak Shilat, p. 428). He says that some tunes act upon one's soul, others stir up violence, others awaken all types of inclinations, etc. If the tune entices negative inclinations it is forbidden, but if it spiritual repairs a person it is permissible. In order to know if the tune is kosher you can look at how the body moves when one listens to it.
3. Kosher Singer – Ha-Rav Moshe Feinstein discusses this idea in Shut Igrot Moshe (Even Ha-Ezer #96) that when people listen to songs or sing someone's songs, they give honor and respect to the singer. If the singer is a sinner, we do not want to provide him with honor and respect. A singer is like an educator – it is not just a technical skill but a spiritual one. I am not discussing what "Sefer Ha-Kuzari" says that a singer is like a Levi in the Temple. We do not have the Temple or Levi'im (with certain genealogy). What is a kosher singer? A Jew who keeps the 613 mitzvot or a non-Jew who keeps the seven mitzvot incumbent upon non-Jews.