Introduction to Pitch Systems in Tonal Music: The Minor Triad and a Circular System of Thirds

The Minor Triad and a Circular System of Thirds

This presentation introduces the 6:5 minor third and 10:12:15 minor triad. The tonal pitch system uses major and minor triads, and the pitch system in use has to accommodate this. These sounds and ratios lead to the construction of a diatonic circle of thirds and a further goal; tune a diatonic set so that all I IV V major and i iv v minor triads are pure whole number ratios.