Major and Minor - Intonation and Tuning

Intonation and Tuning

Underlying perceived musical tuning of intervals is the frequency relationship expressed as a fraction. Simple fractions can sound more harmonious than complex fractions; for instance an octave is a simple 2:1 ratio and a fifth, also concordant is the relatively simple 3:2 ratio. The table below gives approximations of a scale to ratios that are rounded towards being as simple as possible.

In just intonation, a minor chord is often (but not exclusively) tuned in the frequency ratio 10:12:15 ( play). In 12-TET, or twelve-tone equal temperament (now the most common tuning system in the West), a minor chord has 3 semitones between the root and third, 4 between the third and fifth, and 7 between the root and fifth. It is represented by the integer notation 0,3,7. The 12-TET fifth (700 cents) is only about two cents narrower than the just perfect fifth (3:2, 702.0 cents), but the 12-TET minor third (300 cents) is noticeably (about 16 cents) narrower than the just minor third (6:5, 315.6 cents). The 12-TET minor third (300 cents) more closely approximates the 19-limit (Limit (music)) minor third (19:16 Play, 297.5 cents, the nineteenth harmonic) with about two cents error. Ellis proposes that the conflict between mathematicians and physicists on one hand and practicing musicians on the other regarding the supposed inferiority of the minor chord and scale to the major may be explained due to physicists' comparison of just minor and major triads, in which case minor comes out the loser, versus the musicians' comparison of the equal tempered triads, in which case minor comes out the winner since the ET major third is about 14 cents sharp from the just major third (5:4, 386.3 cents), but just about four cents narrower than the 19-limit major third (24:19, 404.4 cents); while the ET minor third closely approximates the 19:16 minor third which many find pleasing.