I added my own guitar and singing for background and ideas.
Drawing with light is very time consuming with a digital camera that only allows up to 4 seconds exposure time and up to 40 seconds in between taking pictures so I added stop animation and pictures to the video.
Step 1: Audio
I like to play Oasis' Wonderwall so I first recorded it with my Digital Camera. Once I started adding a lot of animation the sound quality was bringing down the video so I re-recorded guitar and voice separate using garage band.
Step 2: Video
You could make videos to go along with your audio.
I wanted to try light exposures so I tried this first. It was very time consuming but the effect is worth it. I just set my camera to nightmode, made sure the room was dark enough that when the camera focuses (on my camera its half pressing the button) to the longest exposure time. My camera will take up to a 4 second exposure so it says 4" on the display. Then I set it to take 3x pictures at a time and use a tripod or stable surface. There are already great instructables on light drawing:
Stop animation is easy to do with a digital camera. I learned just from trying it. If you plan to have your video small, like youtube sized, then set your camera to the smallest picture. I always keep mine on 640x480 and "fine" setting to take quicker pictures that take up less space. I turned off the flash to keep the mood of the song and not have to worry about lighting. Take lots of pictures! For the 4 minute song I had 559 unique pictures for stop animation and light exposure. I repeated a lot of pictures so you really need a few for animation. Each picture was less than 200k so they didnt take a lot of time to work with in imovie.
I know a little flash animation so I used the drawing of myself and added one of Mia. I imported a picture, outlined main features and keep legs and arms on seperate layers to animate. Flash is not hard to learn but if you've never used it before expect to spend some time learning its quirks.