In music, extended technique is unconventional, unorthodox, or non-traditional methods of singing or of playing musical instruments employed to obtain unusual sounds or timbres. Composers’ use of extended techniques is not specific to contemporary music (for instance, Hector Berlioz’s use of col legno in his Symphonie Fantastique is an extended technique) and it transcends compositional schools and styles. Extended techniques have also flourished in popular music. Nearly all jazz performers make significant use of extended techniques of one sort or another, particularly in more recent styles like free jazz or avant-garde jazz. Musicians in free improvisation have also made heavy use of extended techniques.