Tuning as an Element of Musical Expression

In performance, it is common for musicians to use different tunings according to whether or not the music is primarily melodic or primarily chordal. Melodies can be made more "expressive" by using large major seconds and small minor seconds (such as those found when the tuning slider has beta values between approx 701 and 705 cents). When the music is more chordally based, the meantone tunings around 1/4-comma may be preferable because major and minor triads are more in tune.

In many of the continua, there is a tension between the tuning requirements of melody and the requirements of harmony. Fortunately, the tuning sliders can be manipulated on a phrase-by-phrase or even note-by-note basis to suit the music as it is performed. This can be viewed as a simulation of the techniques of intonation used by string players (or wind players, or singers) who continuously adapt between expressive intonation for melodic passages, meantone or Just Intonation for harmonic passages, and 12-TET when playing with a fixed-pitch instrument like the piano.

The sliders can also be used in the same way that pitch bend is used to help connect melodies and phrases and to add expressive ornamentations. A unique feature of the tuning sliders is that they operate polyhonically, where all the notes of a chord are bent together, each in its own direction. Linking together the tuning sliders of a group of performers under the control of a single tuning "conductor" opens up intriguing tonal and compositional possibilities.

The contrast between desirable features of melody-based tunings and those of harmony-based tunings can also be softened by setting the tone diamond to temper the overtones. At the extreme setting on the right of the diamond, the sensory consonance is maximized for any setting of the sliders (that is, for whatever tuning is currently chosen).