Curse of The Sandman (for solo microtonal guitar [fretted in 8-EDO] + electronic effects)

Awarded First Prize in the 7th International Microtonal Guitar Competition (2023), Microtonal Guitar Institute (Istanbul Technical University).

8-EDO (Equal Divisions of the Octave) is the tuning system derived by dividing the octave into eight equal parts of exactly 150 cents each. A guitar fretted in 8-EDO adds a further dimension in that each string can produce a different set of eight notes depending on the choice of tuning/scordatura applied. This yields a specific overall ‘note-pool’, containing a complex array of quarter-tone pitches. Certain notes may appear only in certain registers; and some pitch classes common to 12-TET (i.e. where each string yields the same twelve notes) may be eliminated altogether. This method of note/pitch generation presents various expansions and limitations both sonically and physically on the guitar, affording novel performance possibilities.

Each string generates a pitch-set comprising two diminished seventh arpeggios, each displaced by 150 cents. Though these pitch-sets inherently yield much dissonance, they also provide excellent approximations of 11-limit Just ratios 12/11 (undecimal neutral second » 150.6¢) and 11/6 (undecimal neutral seventh » 1049.4¢),and a very good approximation of the 13-limit Just ratio 13/10 (tridecimal semisixth » 454.2 ¢).

Curse of The Sandman is written for any microtonal guitar fretted in 8-EDO (or any microtonal guitar capable of producing the equivalent note-pool, e.g. adjustable microtonal guitars; guitars fretted in 16-/24-EDO etc.), and makes explicit use of any well-approximated Just intervals throughout. The use of electronic effects/pedals should be applied as directed by the score; specific settings however, may be decided by the performer. Effects may be added as part of a direct signal chain (i.e. if using an electric or electro-acoustic guitar) or via a microphone (i.e. if the guitar is acoustic).