I am a avid listener of classical music and have picked up bits and pieces of German from it (I have picked up a little French as well, but I am comfortable with that language to that may be a different story). Will this "learning" help or hurt me when I go to actually learn German?
This kind of learning will help you memorize some words. By listening to music and watching movies, you can build your vocabulary. So it will be beneficial for you when you learn German.
However, you have to talk to people whose native language is German or who are fluent in German in order to improve your listening skills. You can talk to them and you will become very fluent.
I think it will have some limited benefits. By being exposed to the sounds of the language, it will not be so unfamiliar when you start learning the language. You may begin noticing some unfamiliar phonemes, and this will give you a basis for pronunciation when you start learning. This is especially true if you're self-studying - sometimes the pronunciation guides are difficult to follow, but if you've heard the sounds before, and you can make a connection, then you'll learn them quicker. By being more familiar with certain sounds, you may be able to imitate them sooner.
Also, you'll just be more familiar with the some of the words. You may not know the meaning yet, but when you encounter a word that you remember hearing a lot in music, you'll be more ready to learn that word.