@ZRiMusic I didnt mean his influences because they doesnt matter at all. At that time Brahms was also influenced by Mühlfeld but this is not the most important thing.There is something more, not only random improvisation - musical context... some message or idea. If you change the music you obviously change the context and after that it becomes "nothing but a traditional czardas improvisation" as you suggest. That is not Brahms anymore.