Internal notes (as in music)

As an 'alongside' to the internal vibration thread, does anyone else hear, actually hear, musical notes that seem to be inside their head when they are trying to get to sleep?

When it happens to me it is a major third shift of note – so only two notes up and down repeatedly. If I put my fingers in my ears I can't hear it but and if I sit up or get up I can't hear it. It's just when my head is on the pillow.