Bohuslav Martinů was a Czech composer of modern classical music. Martinů wrote 6 symphonies, 15 operas, 14 ballet scores and a large body of orchestral, chamber, vocal and instrumental works. Martinů became a violinist in the Czech Philharmonic Orchestra, and taught music in his home town. In 1923 Martinů left Czechoslovakia for Paris, and deliberately withdrew from the Romantic style in which he had been trained. In the 1930s he experimented with expressionism and constructivism, and became an admirer of current European technical developments, exemplified by his orchestral works Half-time and La Bagarre. He also adopted jazz idioms, for instance in his La revue de cuisine ("Kitchen Revue").
In the early 1930s he found his main fount for compositional style, the neoclassicism as developed by Stravinsky. With this, he expanded to become a prolific composer, composing chamber, orchestral, choral and instrumental works at a fast rate. His use of the piano obbligato became his signature. His Concerto Grosso and the Double Concerto for Two String Orchestras, Piano and Timpani are among his best known works from this period. Among his operas, Julietta and The Greek Passion are considered the finest. He is compared with Prokofiev and Bartók in his innovative incorporation of Central European ethnomusicology into his music. He continued to use Bohemian and Moravian folk melodies throughout his oeuvre, usually nursery rhymes—for instance in Otvírání studánek ("The Opening of the Wells").
His symphonic career began when he emigrated to the United States in 1941, fleeing the German invasion of France, to compose his six symphonies, which were performed by all the major US orchestras. Eventually Bohuslav Martinů returned to live in Europe for two years starting in 1953, then was back in New York until returning to Europe for good in May 1956. He died in Switzerland in August 1959.

(Franz) Joseph Haydn was a prolific Austrian composer of the Classical period. He was instrumental in the development of chamber music such as the piano trio and his contributions to musical form have earned him the epithets "Father of the Symphony" and "Father of the String Quartet".
Haydn spent much of his career as a court musician for the wealthy Esterházy family at their remote estate. Until the later part of his life, this isolated him from other composers and trends in music so that he was, as he put it, "forced to become original". Yet his music circulated widely and for much of his career he was the most celebrated composer in Europe.
He was a friend and mentor of Mozart, a teacher of Beethoven, with whom he formed the First Viennese School. He was also the older brother of composer Michael Haydn.