Our language doesn't provide many words for describing music. I have noticed this when trying to promote concerts. So I suppose the lack of a good word for describing the union of souls that are singing music is no surprise.

(Sorry, Jeremiah, I don't think "grok" is going to make the lexicon.)

I think this lack has to do with the fact that we process sound in the back of the brain, the more primitive part. It is older far than the front left part which is mostly responsible for language.