It's the law of linguistic transversals, silly.
"Though original song was sung as a language in Japanese."
=
"Though original song was sung, as a language, in Japanese."
=
"Though original song was sung, in Japanese, as a language."
or, alternatively, =
"Though original song was sung, as a language, in Japanese."
Of course commas aren't required for grammatical correctness at all in that statement, only useful for readability.
So when you see a multi-perceptual statement like that, you choose the context that makes sense, not the one that doesn't.
