Franz Joseph Haydn was critical in creating the musical structure of the symphony, taking short motifs and developing them into longer works through repetition of themes with developments and variations of harmonization. Haydn was also one of the first composers to write extensively for string quartets in their formation of two violins, viola, and cello.
Childhood prodigy Wolfgang Amadeus Mozart went on to become one of the most prolific composers ever, exploring and advancing every organizational format. His music is marked by rich harmonization and often used contrapuntal rhythmic patterns based on influences from the Baroque period.
Ludwig van Beethoven's early compositions showed the influence of his studies of Haydn and Mozart, although his work used modulation more extensively than either of his predecessors. As his work matured, he expanded the use of recurring theme to explore all facets of harmonization and rhythmic effect in a composition, creating symphonies of great power and extended length.