Pre-Nostradamus tunes from 1999

Ton Scherpenzeel has worked regularly with Dutch theatre company Opus One. Their 1999 production "Klokkenluider van de Notre Dame" ("The Hunchback Of Notre Dame") was one of the musical productions for which Ton wrote the music. And this is an interesting one: some of the themes that Ton wrote were later used again for the Kayak album "Nostradamus".

The track "Het Hof Der Wonderen" ("The Court Of Miracles") evolved into "Dance Of Mirrors", as you can hear here:
http://www.box.net/shared/4i7knjmapu

and the Nostradamus Overture (as well as some other parts) was based on "Verlaten En Alleen" ("Lost And Alone"):
http://www.box.net/shared/uy555mdpi9

Is this a new discovery? Is Ton guilty of self-plagiarism? I don't think so; In interviews and in one of his blogs on the Kayak site, Ton has explained this recycling of tunes: the Opus One productions are only performed for a short time, and it is very unlikely that they will ever get a re-run. And the music was released on CD, but the CD's were only sold to a handful of people. Ton really liked the tunes, and he thought it a shame if nobody would ever hear them again. He therefore decided to re-use them for Kayak.

Copyright on the tunes: 1999 Ton Scherpenzeel / Opus One
More info on Opus One: visit www.opusone.nl