I added a tuba part, a music box, and I used the existing backup vocals as the modulator source in a vocoder.

None of this is particularly appropriate to the song, but I was looking for crazy out-of-the-box ideas, and I think it kind of works.  Kind of.

I'm at work now, but my computer at home is allegedly uploading stems as I type this.  I'm a little concerned that it hasn't finished yet.

I may redo the music box later.