In Chapter 6, I discussed Charles Bonnet syndrome, a variant of visual hallucinatory experience that occurs often in the context of visual loss. In this chapter, I turn to musical hallucinosis, a condition in which the predominant feature is the perception of music in the absence of external stimulation. It often occurs in the context of hearing loss, but not exclusively so. This means that it has been considered by some authors as the auditory equivalent of Charles Bonnet syndrome.