From video description:
Collected executions. World elite of Russian piano school. Denis Matsuev, “Unknown Rachmaninoff”: suite, variations on a theme of Corelli, fugue. Great Hall of Moscow conservatoire.
While studying in the Conservatory Rachmaninoff created a score which could not be performed because of the lack of instruments in the Conservatory orchestra. The composer executed the piano version himself and passed the script to Tchaikovsky, which was mentioned in a letter dated 1981. The trace of the score was lost for more than a century and was found only several years ago in the archive of the Glinka museum, in the collection of professor Siloti, Rachmaninoff’s professor. The manuscript bore the name neither of the composition, nor of the author. But the experts established that it was made by Rachmaninoff and that it was the very lost piano suite D minor. Alexander Rachmaninoff, the grand-son of the great composer and the keeper of the Rachmaninoff family heritage, entrusted Denis Matsuev with the first record of the archival score. The record was made in May 2007 on the villa “Senar” in Switzerland, where Rachmaninoff lived in years 1929-1940. Especially for the record they restored the “Steinway” piano made in 1928 – it is a well-known fact that Rachmaninoff was a big “Steinway” fan and popularizer, and the company gave him the instrument as a gift. Denis Matsuev’s CD “Unknown Rachmaninoff” was produced by the “Grammy”-awarded Philipp Nedel.