Haydn was born on March 31, 1732 in Rohrau, Austria. His musical orientation began at a very early age: At 6, he became an apprentice to a relative in Hainburg, and he eventually learned how to play the harpsichord and violin, as well as sing in the town's church choir. At the age of 8, he moved to Vienna to study under the music director of St. Stephen's Cathedral. He was there until 1749, when he left to began freelancing as a musician, training himself in music theory and composition while doing so.
By the mid 1750s, Haydn's skill and popularity had grown noticeable enough to attract the attention of the aristocracy, eventually landing him stints as a music teacher. In 1757, Haydn landed his first full-time gig under Count Morzin, where he began the first few of his 106 symphonies. From there, Haydn moved to become Vice Kapellmeister (music director) to the wealthy Esterhazy family in 1761, and then full Kapellmeister in 1766.
Here, Haydn was astoundingly prolific and busy, running the entire musical operations of the Esterhazy palace. However, even as he enjoyed secure employment, he still freelanced, the result of which produced works like the Paris symphonies (1785 to 1786) and "The Seven Last Words of Christ on the Cross," (1786) commissioned by French and Spanish patronage, respectively.
In 1790, the new head of the household shut down the entire music program at the Esterhazy residence. However, by this time, Haydn enjoyed immense popularity as a masterful and prolific composer, so he capitalized on his freedom by making trips to England, where he held concerts and composed some of his best and most famous works. His most well-known piano trio, nicknamed the "Gypsy Rondo," was composed there in 1795, as was his twelve-part "London Symphonies."
In 1795, Haydn returned to Vienna, where he spent his twilight days, wealthy from his years of musical service. He was still productive during this period, as evidenced by nine string quartets and two oratorios, among other works. Unfortunately, a progressing illness in 1802 curtailed his prolificacy. He died on May 31, 1809, at the age of 77, shortly after a Napoleon-directed French army attacked the city.
Haydn is considered one of the creators or formative figures of the symphony, sonata and string quartet. His music is trademarked with humor: the "Surprise" symphony (1791), for instance, which was an entry in the "London Symphonies," is most notable for its sudden, loud chord to get audience members out of drowsiness during the slower portions of the music. It is estimated that Haydn composed more music than virtually all composers in the preceding 150 years. He was close friends with Mozart, and Beethoven was one of his pupils.