The term comes from "Wanted Words", a book (or set, actually, as there are two volumes) by Jane Farrow that grew out of her fascinating CBC show that no longer airs (for reasons passing understanding and most likely having to do with funding). It refers to a song that will not get out of your head no matter how hard you try. The apparent remedy is a brain-rinse, but that's only if you dislike the aneurythm more than the rinse, as the latter runs the risk of becoming the former.
Most are a nuisance.
Mine, however, is pretty okay for today. Michael Bublé is bouncing around in my head singing "Fever".
Katherine has been listening to Annie Haslam's (of the progressive rock band Renaissance) superior recording of Mike Oldfield's composition, "Moonlight Shadow" as well as Eimear Quinn singing "The Voice".
Strange mix, but it works….