Microtones are intervals smaller than a half-step,
the most common of which are quarter-tones. I will play a quarter-tone
scale to demonstrate the extremely close distances between pitches [Clip
3]. The execution of quarter tones requires the performer to either employ
a different fingering or bend the pitch up or down with the embouchure.
Two examples will demonstrate two effective uses of quarter tones: Pertout's
Echoes from the Past and Brian Ferneyhough's Carceri d'Invenzione,
IIb (The Dungeons of Invention). In the Ferneyhough passage, we hear
quarter tones as well as smaller microtones.