The emotional landscape of a film is frequently created by music. Adding music to your instant movie makes it seem “smoother” and give your story a sense of forward motion. Music is such a ubiquitous part of movies that you almost don’t notice it unless it’s absent.
Personally, I think you should create your own music track if you really want to call yourself an instant moviemaker, but I wouldn’t blame anyone for resorting to library music. Producing music can be just as time-consuming as producing film, so you might want to focus on your strengths. On the other hand, if you create your own music, you completely eliminate many copyright headaches.
Even if you’re not a musician, there are plenty of great software packages that can help you create a compelling music bed that helps propel your movie. And if you are a musician, you still might want to take advantage of a music creation program, just to avoid the complexities of creating a studio recording. When you create your music track entirely on the computer, it’s easier to get a seamless track without extraneous noise and other distracting problems.