Wolfgang Amadeus Mozart was an Austrian composer and musician. He is considered one of the most influential composers of the classical era. Mozart's music encompasses a wide range of genres, including symphonies, operas, chamber music, and piano music. His compositions are known for their beauty, complexity, and emotional depth. Mozart's most famous works include his Symphony No. 40, his opera 'The Marriage of Figaro,' and his piano concerto No. 21.