Well, adding background music it’s hard at all. On top of that, it’s easier than most people think. You can use a simple app you find on the apple store and not only, and everything is done in some seconds. Of course, if you use it for bigger projects, then it’s better to get in contact with music promotion companies since there are a lot of legal details you should take into consideration. However, I’m sure after you finish one video, everything will become easier for you, and you won’t need help from anyone.