The Rosegarden Codicil: Rehearsing Music in nineteen-tone equal Temperament

We are using the term ‘microtonal tuning’ here to mean simply any tuning with more than twelve notes per octave, though we realise that the term is sometimes defined more broadly. For example, the definition could be so broad as to include all tunings other than the one based on the ubiquitous Western tempered scale with twelve equally-spaced steps per octave (hereinafter abbreviated as 12-ET). Scales with seven or eleven equally-spaced steps per octave, for example, could reasonably be considered microtonal. On the other hand, it would seem somewhat eccentric to call the various historical varieties of just and mean-tone tuning with twelve tones or fewer microtonal just because they are different from 12-ET. So we have framed our definition as indicated above merely with our present practical purpose in mind.