Mstislav Leopoldovich Rostropovich (27 March 1927 – 27 April 2007) was a Russian cellist and conductor. He is considered by many to be the greatest cellist of the 20th century. In addition to his interpretations and technique, he was well known for both inspiring and commissioning new works, which enlarged the cello repertoire more than any cellist before or since. He inspired and premiered over 100 pieces, forming long-standing friendships and artistic partnerships with composers including Dmitri Shostakovich, Sergei Prokofiev, Henri Dutilleux, Witold Lutosławski, Olivier Messiaen, Luciano Berio, Krzysztof Penderecki, Alfred Schnittke, Norbert Moret, Andreas Makris, Leonard Bernstein, Aram Khachaturian and Benjamin Britten.