Music Theory

Here is a preview of some of the lessons included in Musicopoulos

Major Scale Relationships

Understanding The Relationships Between Major Scales and How the Circle of 5ths Works

In the previous lesson, we constructed the Major scale by determining the lower and upper tetrachords, both of which share the same 2-2-1 patterns. It follows then that the lower tetrachord of one Major scale can represent the upper tetrachord of another Major scale. Lets look at an example so that we can visualize this concept.

The C Major scale can be constructed by first deriving the lower tetrachord

Major Scale Relationships Example 1

next, we move up one wholestep to G

Major Scale Relationships Example 2

and finally construct the upper tetrachord

Major Scale Relationships Example 3

Now, the upper tetrachord of the C Major scale becomes the lower tetrachord of the G Major scale. We can then determine the starting note of the upper tetrachord of the G Major scale by moving up one wholestep from the last note of the lower tetrachord

Major Scale Relationships Example 4

And finally derive the upper tetrachord of the G Major scale

Major Scale Relationships Example 5

This relationship exists between all the Major scales and when continued will reveal the following cyclic pattern

Major Scale Relationships Example 6

When we follow this pattern in a clockwise direction, it is know as the Circle of 5ths, as the 5th note of each Major scale becomes the 1st note of the next Major scale in the sequence.

When we follow this pattern in a counter-clockwise direction, it is know as the Circle of 4ths, as the 4th note of each Major scale becomes the 1st note of the next Major scale in the sequence.

Understanding and memorizing the Circle of 5ths/4ths helps us understand and describe musical relationships and becomes an essential part of musical composition, harmonization, building chords and working with different keys.