[ Ref. https://www.youtube.com/watch?v=rOPe9C281q0
 

The waltz is an extract from Godard's Flute Suite (Mvmt 3): Godard
Suite for Flute and Piano.  Jan Kees de Ruiter made the waltz from
the suite for the organ, as I recall.  Hope this solves the mystery!

With kind regards,
Adam Ramet
http://www.pianopavilion.com/