Chapter 4
The Rectangle of Fifths will help you identify the key signature of any major/minor, sharp # or flat ♭ key starting from that tonic note position
The Rectangle of Fifths is based on assigning a numeric value to each note within a single octave.
We have developed the Rectangle of Fifths as an easy alternative to the Circle of Fifths. We will explain in detail as you scroll down the page.
Positive Number: Sharps
Negative Number: Flats
Remember
The tonic is the first note of a scale.
Chopsticks are the two black keys together and the fork is the three black keys together.
How to Remember the Numbers on the Rectangle
The two black note positions between C and E are commonly known as the Chopsticks. They look like a pair of chopsticks and their first position is C♯.
The three black positions between F and B are commonly known as the Fork. They look like a three-fingered fork and their first position is at F♯.
Even values are at the Chopsticks and start at 0 and are incremented by two.
Odd values are at the Fork and start at -1 and are incremented by two.
What do these Numbers Mean?
Rule for key signature:
A positive keyboard position value on the Rectangle of fifths equals the number of sharp # black positions for major keys starting from that white keyboard position. A positive value displayed is a key signature with sharps (#).
The negative -1 keyboard position value advises one flat ♭ black positions for the major F key. A negative value displayed is a key signature with flats (♭).
Positive Number: Sharps
Negative Number: Flats
We will discuss this further in the next lesson.