In addition to my tinnitus chorusing along with earworms, sometimes those earworms just seem to pop up out of nowhere, or some “Fibber McGee’s Closet” of memories. . .
One occasional source of memories insinuating themselves as earworms is children’s songs learned in early-mid childhood. I recall 4th Grade music class (what, maybe once or twice a week?) which was held in the school library for some reason. The music book was a faded red cloth-covered book, and when one of the songs from that class crops up, I see the page the song was on, the music, and the lyrics, even, from time to time, illustrations accompanying the song. *shrugs* Visual memory always seems to work better for me when it’s associated with music, especially sheet music, etc.
Just one of those things.