Composers of the Classical period wrote music between approximately 1750 and 1820. The most significant composers of the Classical period are Haydn, Mozart and Beethoven. The Classical period was a time in which composers wrote with balance, order and clarity of individual musical lines in mind. These composers worked and lived in Vienna, Austria, and collectively formed a portion of the First Viennese School.
Haydn, the "father" of the string quartet, wrote extensively for strings. He wrote 68 pieces for string quartet as well as numerous symphonies and instrumental works. Nikolaus Esterházy, a member of the aristocracy, and his family employed Haydn throughout his life. Haydn was fortunate to have an orchestra at his disposal to perform and experiment with new compositions as it allowed him to have a musical lab to play with new ideas. While he traveled often, he was mostly isolated from other composers of the time and was free to write as he wished.
Mozart had an enormous output and perfected the Classical style. He was 35 when he died, but in that short time, he created over 600 musical works. His operas and symphonies are among the best in musical literature and are frequently performed. Mozart wrote and performed for royalty at an early age, and was famous throughout Europe as a child prodigy.
Beethoven redefined the Classical period with his innovations in the symphony and his expansion of harmonic language. He music was so powerful and influential, it created a bottleneck in the world of Classical music. He initially wanted to study composition with Mozart, and even moved to Vienna to do so in 1787, but upon Mozart's death, he studied with Haydn. This relationship with Haydn was short-lived as Beethoven began to suspect that Haydn was jealous of and biased against his music. His late works overlap into the Romantic period, creating a seamless transition between Classical and Romantic music.