Beethoven's "Middle" period of composing began shortly after he was beset with deafness. His music of this period tended towards large-scale works expressing heroism and struggle, and included six symphonies, commencing with the "Eroica", and including the rich and penetrating Fifth Symphony. Other works include the last three piano concertos and his only violin concerto, five string quartets (Nos. 7 - 11), many piano sonatas, including the Waldstein and Appassionata, and his only opera, Fidelio.