Tertian harmony describes music and chords constructed with thirds. Based on the diatonic scale, and the basic concept of intervals, these thirds are either minor (an interval of 3 semitones) or major (an interval of 4 semitones). Tertian harmony forms the 4 triads of music as well as 8* of the most common seventh chords.
*There are 8 tertian seventh chords, but only 7 that contain four distinct notes. We’ll get to this later in our matrices.
A closer look at Tertian Harmony
A common way of describing tertian harmony is with the scale degrees of the Diatonic/Major Scale.
So let’s look at the C Major Scale to get a better idea of what tertian harmony is:
Continue reading “Understanding Tertian Triads and Seventh Chords”