In jazz, a tritone substitution is the chord substitution of a chord with a dominant chord that has its root a tritone away from the original. The tritone substitution is one of the most common substitutions found in jazz and was the precursor to more complex substitution patterns like Coltrane changes. Tritone substitutions are sometimes used in improvisation—often to create tension during a solo. Though examples of the tritone substitution in major repertoire appear as early as the 1910s, for instance in the rondo of Mahler's 9th Symphony, they were first used extensively by musicians such as Dizzy Gillespie in the 1940s, Duke Ellington, Art Tatum, Coleman Hawkins, Roy Eldridge and Benny Goodman. For example, using C (D) major instead of G major in the key of C major (C is a tritone away from G).