I mostly translate songs for singing. As a rule, I would only consider translating a song, if I like it musically, and if it does not have a legitimate adaptation in any language that I can intelligently sing in. Those include Russian(native), English, Hebrew (both semi-native), and Spanish ( fluent when I need to be)
I am only interested in producing translations that can be sung to the original melody or to the original melody with acceptable variations, which I am planning to outline at some point soon.. If the original has rhyming, then I am making an effort to have the same rhyming structure in the translation. Under these conditions, it is almost never possible to have a literal translation, but I am always trying to stay as close to the original as possible.