In Panel B, A indicates that the tone measure is the current
quarter TONE minus the previous
quarter TONE.
So that I knew what it was supposed to be, then I could just aim a
quarter tone under or over or around.'
His average vibrato extent was a little less than a
quarter tone up and down from the center frequency, similar to vocal vibrato.
For example, it would be helpful for Macdonald to include correct notations for examples in the
quarter tone section to indicate whether the fingerings raise or lower the pitch, though presumably the idea is to experiment and discover for yourself!
Earlier in his letter to Bernard, he had written, "I remain in the grip of sense-perceptions"; and, on December 23rd of the same year, he would write to him that "an optical sensation is produced in our visual organs that allows us to classify by light, half tone, or
quarter tone, the planes represented by color sensations.
In the piece I used various forms of singing, an intimate even voice, and fast rap declamations, and I also used a sixteenth-tone piano, a harp tuned to quarter-tones, a sample with snatches of voice and the singers' breath, a lot of percussion instruments, like the chromatic octave of Java gongs, two octaves of cow bells, 3 octaves of boo-bams, a vibraphone tuned a
quarter tone higher ...
I understand it as a unification of two spaces: the first is the twelve-semitonal space, and the second is another twelve-semitonal space a
quarter tone higher.
By the way, fans of aliquot registers will be intrigued to hear that one of Thoresen's basic folklore inspirations is a kind of equivalent to our Czech "halekani" (a form of yodelling), where the phrasing is formed by a twelfth interval raised by perhaps a
quarter tone. As well as being a composer with a rich and varied output, Thoresen is also a teacher and theoretician who has created and elaborated a theory of the typology of musical objects and analytical methods based purely on the sound perception.
Murail rounds most of the tones to the twelve-equal-tempered scale, except where pitches fall almost exactly on a
quarter tone. These are indicated in Example 13 with arrows.
The amplitude of a bel canto vibrato ranges from a
quarter tone to a half step, and its rhythm is 5 to 7.5 vibrations per second.
The brass instruments impart acoustical beating to the texture by sustaining notes a semitone or
quarter tone apart.