Major Scale, Cycle of Fifths, and discovering the Black Notes

On the Harmonic Table, one of the first things you notice is that for any note, the note immediately above it is it's fifth. Eg above C is G, above G a D, and so on. If you keep going, you'll play every note in turn and end up on the same note. Hence the name 'Cycle of Fifths'.


One of the most widely used scales is the Major scale. On the Harmonic Table, one octave can be played (see diagram on the right) in the order of the red numbers.

A Major scale is made up of tones and semitones. A semitone is one step and a tone is two steps up in pitch. The gaps between notes are:- Tone, tone, semitone, tone, tone, tone, semitone. Semitones are between 3-4 and 7-8.

Play a C-Major scale on the Harmonic Table using the pattern above.
What happens if you try carrying on the same pattern in the next octave?

The Cycle of Fifths has the property that each time you move your root or starting note up a fifth, to play the same (major) scale, you add a black note (or "sharp" or #). This is reflected in the key signature.

By convention C major is the scale which has no sharps and flats, so let's start on C and play all 8 notes (pattern as above).

Now notice that if you play the same pattern starting one note up on the Cycle of Fifths (ie G) (ie red 5 in the diagram above) the second to last note you play will be a black note - F#. So G major has one sharp (F#) in its key signature.

Now move up another fifth. Play the same pattern. Note that this time there are two black notes involved (F# and C#).

Keep going. (Move up another fifth). What do you find? Which key are you playing in? Which other black note has joined?

Keep going.

What happens after you're playing all five black notes in your scale?
(On a piano keyboard the five black notes are arranged in two's and three's
On an Harmonic Table they're in vertical lines of five).

Keep going. Now there are more "white" notes coming back into your scale. Instead of being referred to as sharps, black notes get referred to as "flats". Should it be B-flat major or A-sharp major? Find a reputable music theory source to clear up when black notes are said to be sharps or flats. You may be surprised to learn that sometimes white notes are referred to as sharp or flat (find E# and C-flat), and that double-sharps and double-flats are sometimes required.

So, notice...

Disclaimer: I could be wrong ... always consult a professional. :-)

Last Updated : Dec 17 2015

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