Terrible Earworm

I am having trouble knowing how much time to allot for my homework assignments. Several times I’ve would up working past 1 am. I have been a night owl for many years and and I seem to have my best focus around 1 and 2 am, but…now I have to get up at 7 in order to catch the bus. 5 hrs of sleep makes for a long stressful day. This past week I came into a Wednesday very short on sleep and had not allotted enough time to practice for voice lessons. Since one of the new songs I’m learning is in Italian, I spent time on the bus (and in the stairwell) practicing the Italian, saying the syllables as clearly as possible, with very pure vowels. Over and over. In rhythm, with the tune in my head. The combination of the lack of sleep, over-studying, and adrenaline about the lesson led to the worst earworm I have had in a very long time. I COULD NOT get the song to stop. It kept playing in continuous repeats. When I came home I was able to take a nap, which helped. I also took a break from that song for a few days. This afternoon was the first I had sung it since Wednesday. The first page is gently playing in the background right now. I wish my brain would move on to pg. 3 which is the part I actually need to work on. “Di belezza non s’aprezza lo splendor / se non vien dun fido cor, dun fido cor. / Di belezza non s’a…prez…ZA lo-o-o splendor, se non vien (carefully) d’un fido (very carefully) co-o-or, d’un (F# major) fido cor!”

I wonder what actually causes the “earworm” phenomenon, and why some days are worse than others.