Mr. Solyom improvises his cadenzas in the heat of the moment whenever appropriate.
Give him a theme and he will create a two-hour recital out of it, complete with Bach, Beethoven and any one of the Romantics -- or "moderns" for that matter. It is quite a sight when 2000 people in the audience submit their suggestions in just so many plastic bags... Or just shout their suggestions...
Solyom is a master of such musical happenings: no wonder TV-producers love him...
An audio sample: Für Elise according to Liszt, from the album Improvisations in Concert. For more of the same, go to the discography page.