The lecture gives an overview on two different approaches to the enharmonic space of 31 tones per octave. Coming from meantone temperament, this tuning is an ideal tool to investigate tonalities constructed by interlocked tetrachords—known as diatonic, which later also results into chromatic and enharmonic situations. All music meant for triad-based harmony can be explored with this tuning that features pure major thirds. Several techniques to analyse and synthesise the improvisation approaches found in jazz are exemplified in meantone temperament on the split sharps keyboard Claviton, the fully enharmonic 31-tone keyboard-instrument built by Georg Vogel.
The second way of looking at the 31 tones is to use the approximations of the intervals of the harmonic series; 31 approaches these just intervals well – tempered fifths, pure thirds, pure septimal sevenths, slightly pseudo undecimal and tridecimal intonations – and therefore can be used as a grid for spectralistic composition and improvisation.
Georg Vogel
