J.J. Johnson (born James Louis Johnson) in Indianapolis, Indiana, (January 22, 1924 - February 4, 2001), was a United States jazz trombonist, composer and arranger. By his early twenties, Johnson developed a technique characterized by flawless precision, and he was the first trombonist to rise to the challenge of bebop music. He remained essentially unchallenged at the forefront of modern jazz throughout his career. Johnson has long been regarded as the leading trombonist of the Post-Swing Era, exerting a pervasive influence on other jazz musicians.