A commonly-used convention for describing scale structure is a number system that uses the major scale as the point of reference…
The system works as follows:
- The number “1” always represents the key that you are in.
- Numbers are assigned to each note in the major scale in ascending order.
- For example, in the key of C: C=1, D=2, E=3, F=4, G=5, A=6, B=7
Scale Degrees for the C Major Scale
And so, the major scale is said to have a scale structure of 1-2-3-4-5-6-7.
- Remember: Any system for naming things is an abstract and arbitrary left-brain construct.
- The choice of major scale as the conventional reference point does not imply that there is something sacred about the major scale.
- Do not let numbers suggest that going up the scale is somehow more important than going down the scale.
- Do not let numbers suggest that a scale is a linear construct.
- Do not let the numbers suggest that a “4: must exist before a “5” can exist… or that a “3” must exist before a “b3” can exist.
Scale Degrees for the C Natural Minor Scale
Now let’s use the number system to describe the scale structure of the Natural Minor Scale…
Scale structure: 1-2-b3-4-5-b6-b7…
Of course, any combination of notes is theoretically possible when building scales. Any combination of scales degrees (numbers) is possible, but don’t worry about the details right now. For the moment, it is sufficient to understand the concept of scale structure, scale degrees, and the number system. You will learn lots more as your studies of scales, chords, and chord progressions unfolds.