Zsolt Gardonyi was born 1946 in Budapest, and is Professor of Music Theory at the Music College, Wurzburg. He says about this piece:
Mozart Changes as the title for an organ work suggests an association with jazz harmony. The international technical language in this field uses the word "changes" to indicate chord progressions. My Mozart Changes revolves around two dance like motives from the final movement of Mozart's last piano sonata in D major... they transform themselves before our eyes and disclose in their cheerful metamorphosis an additional dimension for the word "changes".
I've been doing quite a bit of tweaking of this sample set and I think I'm finally winning! Some Rheinberger coming next week and then we will see whether it's worked!