MODULE 01
Music Theory
Scales · Chords · Intervals · Chord Progressions
Root Note:
Interactive Piano — Click keys or press keyboard (Z–M · Q–U · I–P)
SUSTAIN OFF — SPACE
⌨ Keyboard: Z–M = C4–B4 | Q–U = C5–B5 | I–P = C6–E6Black keys: S D G H J (oct4) · 2 3 5 6 7 (oct5)
C4
Z
S
X
D
C
V
G
B
H
N
J
M
C5
Q
2
W
3
E
R
5
T
6
Y
7
U
C6
I
9
O
0
P
FFT Spectrum Analyzer— static: scale/chord frequencies · live: updates during playback
Frequency Reference
| # | Note | Interval | Abbr | MIDI | Freq (Hz) | Wavelength (cm) | Ratio | Consonance |
|---|---|---|---|---|---|---|---|---|
| 1 | C4 | Unison (Root) | P1 | 48 | 130.81Hz | 262.2cm | 1:1 | Perfect |
| 2 | D4 | Major 2nd | M2 | 50 | 146.83Hz | 233.6cm | 9:8 | Mild Dissonance |
| 3 | E4 | Major 3rd | M3 | 52 | 164.81Hz | 208.1cm | 5:4 | Imperfect |
| 4 | F4 | Perfect 4th | P4 | 53 | 174.61Hz | 196.4cm | 4:3 | Perfect |
| 5 | G4 | Perfect 5th | P5 | 55 | 196.00Hz | 175.0cm | 3:2 | Perfect |
| 6 | A4 | Major 6th | M6 | 57 | 220.00Hz | 155.9cm | 5:3 | Imperfect |
| 7 | B4 | Major 7th | M7 | 59 | 246.94Hz | 138.9cm | 15:8 | Dissonant |
Wavelength calculated at 343 m/s (speed of sound in air at 20°C) · MIDI 60 = C4 = 261.63 Hz · A4 = MIDI 69 = 440 Hz (ISO 16)
Scale Type
C Major
7 notes · C – D – E – F – G – A – B
The foundation of Western music. Bright, happy, stable. Built on the pattern W-W-H-W-W-W-H (whole/half steps).
Interval Pattern
C
W
D
W
E
H
F
W
G
W
A
W
B