yes I have had this problem. I was surprised to find out through google and my treatment providers that its normal and has a name. its called Earworm. no it doesnt mean you have worms, it just means the nerves in your ears and its connection in the brain are reacting in away that is causing audio hallucinations in the form of music. I love it Earworm what a name for it. for me the cause is my MS (Multiple Sclerosis)

your treatment provider can do tests ear/ hearing evaluations, brain scans and such that can tell you what the cause is of your musical Earworm problem is and get you treated for it.