I have had the oddest two earworms plying in the background on the soundtrack of my life, going on the second week now.
One is the phrase, "Sanctus, sanctus" from the Te Deum.
The other is the melody from "Domine fili unigenite J-eh-eh-eh, eh-eh....", etc. from Vivaldi's Gloria -- with a kind of syncopated pop rhythm, a little stop time.
Which is weird, because I have never heard it sung or played thusly.
Not unpleasant to have, really.