The sweater refers to one I gave my wife for Christmas once and she wore every Christmas Eve for the rest of her life. I wanted to start something to commemorate what would have been our 48th anniversary in April. I had also been tinkering with the idea of of a set of variations in which the theme is never stated. These things came together while thinking about the sweater; hence the title.
Lyrics
The lyrics go with the true melody, so they can't be revealed, either.