Copland's graduation piece from his studies with Goldmark was a three-movement piano sonata in a Romantic style. But he had also composed more original and daring pieces which he did not share with his teacher. In addition to regularly attending the Metropolitan Opera and the New York Symphony, where he heard the standard classical repertory, Copland continued his musical development through an expanding circle of musical friends. After graduating from high school, Copland played in dance bands. Continuing his musical education, he received further piano lessons from Victor Wittgenstein, who found his student to be "quiet, shy, well-mannered, and gracious in accepting criticism". Copland's fascination with the Russian Revolution and its promise for freeing the lower classes drew a rebuke from his father and uncles. In spite of that, in his early adult life Copland would develop friendships with people with socialist and communist leanings.