(When) can one listen to Christian music, according to Igrot Moshe?
He states that the restriction is related only to those areas that they use as part of the Christian prayer service. However, he is lenient if the music was composed for general music. So, according to this, if I understand correctly, singing Handel's Messiah may not be problematic [because it was not composed as part of their liturgy].
This seems surprising to me given some of the content, and I questioned it at the time but never saw an authoritative answer. I can't read the Hebrew original.
I used to go to a science fiction convention that attracted a lot of music geeks, and they had a tradition of singing that song once during the convention. I avoided participating because of the content, listened to it some years, and only later considered that that might be a problem. The convention is long gone and this is not a practical matter for me, but I'm still curious.
According to Igrot Moshe, can one listen to music with Christian themes that is not used in Christian liturgy, or must one avoid listening to it even if it was written as "art" and not for use in the church?