Burt Freeman Bacharach was an American composer, songwriter, record producer, and pianist who is widely regarded as one of the most important and influential figures of 20th-century popular music. Starting in the 1950s, he composed hundreds of pop songs, many in collaboration with lyricist Hal David. Bacharach's music is characterized by unusual chord progressions and time signature changes, influenced by his background in jazz, and uncommon selections of instruments for small orchestras. He arranged, conducted, and produced much of his recorded output.