Ludwig van Beethoven was a German composer and pianist. A crucial figure in the transition between the Classical and Romantic eras in Classical music, he remains one of the most recognized and influential of all composers. His best-known compositions include 9 symphonies, 5 piano concertos, 1 violin concerto, 32 piano sonatas, 16 string quartets, his great Mass, the Missa solemnis, and one opera, Fidelio. Born in Bonn, then the capital of the Electorate of Cologne and part of the Holy Roman Empire, Beethoven displayed his musical talents at an early age and was taught by his father Johann van Beethoven and by composer and conductor Christian Gottlob Neefe. At the age of 21 he moved to Vienna, where he began studying composition with Joseph Haydn and gained a reputation as a virtuoso pianist. He lived in Vienna until his death. By his late 20s his hearing began to deteriorate, and by the last decade of his life he was almost completely deaf.