how can Songs help you in learning languages?

Well, speaking from personal experience here, music is a very important tool in language learning. Words, phrases, and even grammar stick better and easier when they are part of a song. Ask any Anatomy student to understand how easy a catchy tune can make memorising. Also, songs present a more 'natural' version of the language, free from the pretensions of a textbook (albeit with its own set of pretensions). Songs can really help you improve your accent, especially your intonation and rhythm. Then there is the motivational aspect of it: if a certain band you like writes in the language you are learning, you are less likely to abandon the language in the future as its novelty weens because you will still want to understand the lyrics. Listening to music from a certain scene also gives you something to chat about with native speakers from that area, thus helping you actually use the languages with them. Make the language part of your life and you will never forget it!