Simplify the following text for a Grade 10 native English-speaking person.
Original: Ashkenazy went on to graduate from the Moscow Conservatory where he studied with Lev Oborin and Boris Zemliansky , winning second prize in the International Chopin Piano Competition in Warsaw in 1955 and the first prize in the Queen Elisabeth Music Competition in Brussels in 1956 .
Simplified: He graduated from the Moscow Conservatory . He won second prize in the International Frederick Chopin Piano Competition in Warsaw in 1955 and the first prize in the Queen Elisabeth Music Competition in Brussels in 1956 .