Simplify the following text for a Grade 9 native English-speaking person.
Original: The Variations on a Rococo Theme is a piece of music for cello and orchestra composed by Pyotr Ilyich Tchaikovsky .
Simplified: The Variations on a Rococo Theme , Op . 33 , for cello and orchestra was the closest Pyotr Ilyich Tchaikovsky ever came to writing a full concerto for cello and orchestra .