My tinnitus began 18 years ago, during a flare up caused by an infection, and has not stopped since. It tends to be a high-pitched sound with several frequencies, like the noise from CRT monitors. It definitely gets worse when other symptoms get worse.
I have also had the impression of listening to music when none was around, but I don't know if that is as uncommon as many people think. The brain often tries to make sense of random inputs, even in people without known nerve damage. This is particularly true in half-waking states called hypnogogia. I suspect we spend more time in these in-between states than others, because this goes along with the sleep problems often reported. The weird images that I see in these situations are not hallucinations, because I can tell they are internal, not external sensory inputs, but they are just about impossible to explain. Even if I were a graphic artist, (which I emphatically am not,) I don't think I could visualize novel images at anything like the rate these appear and morph into others.