02 · Musical Building BlocksLesson 1 of 17About 6 minutes
What you’ll learnWhat musical relationship does Tonic Values reveal, and how can you recognise it?
The Rectangle · Lesson 1
4 | Tonic Values
The full Rectangle range runs from G♭ = −6 through C = 0 to C♯ = +7; the sign and number reveal the key signature.
Lesson 4Foundation
1 · Choose a tonic across the full Rectangle
Negative values reveal flats; positive values reveal sharps; zero has no accidentals.
Selected tonicC
T value0
Key signatureNo accidentals
Keyboard memory map
Select any T value: the tonic is marked, earlier accidentals are blue and the newest accidental is gold.
Chopsticks = even values
Start at C = 0. Move right through C → D → E, adding +2 at each jump.
Start at C = 0. Move right through C → D → E, adding +2 at each jump.
C
0+2→
D
2+2→
E
4Fork = odd values
Start at F = -1. Move right through F → G → A → B, adding +2 at each jump.
Start at F = -1. Move right through F → G → A → B, adding +2 at each jump.
F
-1+2→
G
1+2→
A
3+2→
B
5What is T?
T is the tonic’s Rectangle Position Value.
In this lesson, T is simply the number attached to the selected natural note.
Important distinction: T here means Rectangle Position Value, not the Tone symbol used in scale formulas.
How to remember
Chopsticks: start at C
Starts at C = 0, then D = +2, E = +4.
Fork: start at F
Starts at F = -1, then G = +1, A = +3, B = +5.