Fitzenhagen was proud of the success he had in performing the work,[REF] and in a report he wrote Tchaikovsky after playing it at the Wiesbaden Festival in June 1879, he gave a clue as to why he rearranged the order of variations as he did [REF].
Nevertheless, in one of his occasional fits of insecurity about his work, especially when it came to form, Tchaikovsky allowed the changes to stand [REF].