“although I would wonder about songs praising Yoshke – could songs dedicated to a”z be a problem even if
they’re not part of its official worship?”
I can’t imagine it’s not a problem!
“If it has pritzus, it’s also a problem. Or nibbul peh.”
“I’d forgotten about that. You wouldn’t be allowed to
listen to that even in a non-musical context, though.”
True.
“(Also, by “nibbul peh” you presumably mean foul language.”
I’m not sure what you mean by foul language. I don’t know the source, but I was always told (or thought or assumed) that nibul peh refers to what we always called “curse words” or 4-letter words. But only the ones that actually are bad words and have bad meanings.
I think that it doesn’t apply to those words that Frum people generally avoid (and as kids we always considered to be curse words) but aren’t technically bad words, like the ones beginning with a “d” and an “h”. Not necessarily recommending their usage, but I think they aren’t technically assur.