Sergei Prokofiev was persuaded to add an energetic and optimistic coda to the final movement of his Seventh Symphony, to try to win some much needed cash from the Stalin Prize.
But before he died, a few months later, Prokofiev indicated that the original quiet ending was to be preferred.
Prokofiev told the young cellist Mstislav Rostropovich that he wrote that new ending to gain a-hundred thousand roubles, sorely needed in light of the financial straits that were brought on by his official denunciation a few years earlier.
However he told Rostropovich, “Slava, you will live much longer than I, and you must take care that this new ending never exists after me.”
That is not what happened in the end, but still the work did win the prize.