String players must know how to bow and pluck their instruments, and some instruments are routinely strummed (guitar) or slapped (upright and electric basses); pull-offs, hammer-ons and slides are also part of the common vocabulary of string technique. Woodwind and brass players, who place great importance on proper embouchure and breathing, develop tonguing and articulation techniques. Speed, "cleanliness," dexterity and ease of execution are hallmarks of piano and percussion technique. All professional musicians use technical exercise to increase their grasp of tone, touch, phrasing and dynamics.
Extended techniques for piano include whistling, singing or talking into the piano; percussive use of different parts of the piano, such as the outer rim; and using palms, fists or other body parts or external devices to strike the keys to create tone clusters. Extended technique for woodwind and brass instruments includes flutter-tonguing, continuous breathing or circular breathing and humming while blowing. Extended technique for stringed instruments includes exaggerated vibrato, using altered tunings, playing prepared guitar and tapping on the fingerboard.
Arnold Schoenberg, Bela Bartok, György Ligeti, Iannis Xenakis, Harry Partch, Charles Ives and Krzysztof Penderecki have all composed pieces that required use of extended instrumental techniques. Some instrumentalists devote energy to refining extended techniques. Famed Swiss oboist Heinz Holliger, for example, is credited with extending the technical range of the instrument with his mastery of harmonics, double trills, glissando and multiphonics. Harpist Jacqueline Pollouf lists tapping on the soundboard and thunder (produced by using the open hand to strike the strings and immediately moving away to let the sound resonate) as two common extended techniques for harp.
In Hector Berlioz's ″Dream of Witches' Sabbath" from Symphonie Fantastique, the violinists use an extended technique called "col legno," striking the wood of their bows on the strings. Henry Cowell's "Tides of Manaunaun" features large tone-clusters. George Crumb's "Black Angels" uses extended string techniques, including bowing with glass rods. Charles Ives's "Concord Sonata" uses a long piece of wood to create a cluster chord. Krzysztof Penderecki used extended string techniques in several of his compositions, including "Anaklasis" and "Polymorphia."