What do I do if I have a song stuck in my head during meditation?

This challenge happens to almost all meditators at one time or another. If you get a song stuck in your head, try changing the object of your meditation to sound, focusing on the actual sounds in your environment. Similar to how you deal with thoughts during meditation, Just listen and be present to ambient sounds as you sit. "Hearing" is a good note to use when sound is the primary object in your meditation. If you notice that the song comes into your mind you can note it in your mind as "unpleasant," “pleasant” or "internal hearing," whichever works for you. Then gently redirect your attention back to the sounds in your environment. It's very difficult to have the internal hearing, the song, occupy your attention while you're directing your attention to external hearing.