[KLF] Spot the sample (episode 12B)

Okay ... What exactly IS the sample on "Last Train to Trancentral", "Witchita Lineman was a Song I Once Heard", "Go To Sleep", "No More Tears" and "Lemmings"? You know the one I mean ... It's got trumpets over it on the "White Room" soundtrack, appears just after the monumental thump at the beginning of the LP mix of "LTTT", and is generally the most thrilling moment in pop music in the last twenty years. And it goes ... "diddlediddlediddle-deedee, diddlediddlediddle-deedee ... " Is it a piece of classical music, a sample from another older track, or actually a Drummond and Cauty original? It was certainly the reason why I liked the KLF in the first place (all twenty-three seconds of it). John Not Scots, just Scott-ish.