Music Math 2 + 2 = 3!

Tri is Greek for three, therefore, triad harmony is spelled with three different letters. Now, if triad harmony, arpeggio or chord, has three different letters, then it will also have three different "scale degree tone numbers". Here’s something surprising. There are only nine triads upon which all harmonies are based! These nine triads are created by combining 3rd and 5th intervals. There are three types of 3rd intervals: major, minor, and suspended; and three types of 5th intervals: perfect, diminished, and augmented. When these six intervals are added together - nine triads is the result. See Bass EncycloMedia page 10.

This brings us to music math: 2 + 2 = 3! Let’s think about that. If we add the two tones of the major 3rd interval (1 and 3), with the two tones of the perfect 5th interval (1 and 5), the result is three - the major triad (1 3 5). Remember, no matter how many tone 1’s you add together - the result will always be 1. In other words, in music math: 1 + 1 = 1! Let’s illustrate the nine triads.

In the following nine triad harmonies: C is tone 1, the arpeggio form is “circle four-two”, and the chord form is “circle four-one”.



Enharmonic means the same pitch, but not the same letter or tone number. For example, tone #3 (E#) "sounds the same" as tone 4 (F), but as we will learn in a later lesson, tone 4’s octave: tone 11, is used in dominant eleven harmony. See Bass Fretboard Facts page 102.

There are many other arpeggio and chord harmonies, but they are really just the nine triads with other tone numbers added. See Bass EncycloMedia pages 11 and 12.

These other arpeggio and chord harmonies may also be thought of as the nine triads added together. See Bass EncycloMedia pages 301 through 308.

Till next time, have some nine triad harmony fun - now that you can add...I’ll be listening.