When Igor Stravinsky wrote The Rite of Spring in 1913, he wanted it to begin with an otherworldly sound. So, he wrote for solo bassoon playing a high C--in the stratosphere. The high C on the bassoon was beyond the normal range played by bassoonists, so it was a real reach to hit the note.

Why would he torture bassoonists like that!? Well, the sound of the effortful strain to even play the note was precisely the effect that the wanted for the transcendent opening:**

Stravinsky’s unconventional use of the bassoon for a special effect shows how a composer can stretch the conventional use of an instrument. The term “extended technique” refers to any unorthodox way of playing a musical instrument to create novel sound effects. Musicians continue to use and develop new ways to increase the lexicon of the instrument, as they push the boundaries of their instruments through creativity and experimentation.

Extended techniques fall into a few broad categories:

1. Manipulating the instrument: Making physical changes to the instrument before a performance in order to change its sound.  Probably the best example of this is prepared piano, where the strings inside are manipulated with screws and mutes. This video shows how to prepare a piano for a work by John Cage.
    
2. Changing the the approach: Modifying the manner in which the instrument is articulated. This can involve striking the strings in the piano, hitting a stringed instrument with the wooden part of the bow (see picture: called col legno and used in Berlioz’s Symphonie Fantastique as early as 1830!), or even singing and and playing at the same time. Sometimes, wind players use a flutter tongue (“rolling their r’s” while playing)--here’s a fun demonstration of flutter tonguing on the trombone.
    
3. Artificial distortion: Using external tools to modify the sound. Composers often use electronic feedback from the sound to create additional sonic effects. Here are two pieces for flute by Austin-based Russell Pinkston where you can hear the role of electronic feedback as an intended musical effect. Another non-electronic example of instrumental modification is using helium to alter the sound of a singer’s voice.
4. Microtonal Adjustments: Playing the spaces between the notes, called microtones. These effects work best on string instruments and trombones, because the musician can easily navigate the space between two notes by playing the distance in between (unlike keyed instruments like the clarinet or piano). Here is a piece by Iannis Xenakis for violin that makes extensive use of microtonal pitch bends.

This is just a small selection of the extended techniques used in contemporary music. Check out this extensive compiled list of extended techniques for the french horn alone!

**(Ironically, today, bassoonists practice this orchestral excerpt to perfection for auditions, so it doesn’t sound so strained when bassoonists play it today. For more information about orchestral auditions, click here.)