The "spooky" sound at the end during the fade, is that a theremin, a synth, a musical saw, or someone singing falsetto? - uglinessman 01:47, 21 February 2007 (UTC)
That, and it is in the background during the 'free to come and go lyric'. I always assumed it was Flansburgh singing falsetto, but it very well may be a synth. It is not pitch perfect, which makes it seem more like his voice to me. It is not a singing saw or a theremin.
Doesn't sound like it. Maybe a mashup? --Dunklekuh81