Mapping frequencies.

Western music theory generally divides an octave into a series of twelve notes, called the chromatic scale.

A  A♯/B♭ B C C♯/D♭ D D♯/E♭ E F F♯/G♭ G G♯/A♭

The chromatic scale consists of 12 notes in total: 7 natural notes and 5 enharmonic notes.

Natural notes are A B C D E F G

Enharmonic notes are natural notes highered or lowered by a half step: A♯/B♭ C♯/D♭ D♯/E♭ F♯/G♭ G♯/A♭.

A♯ is pronounced A Sharp.
B♭ is pronounced B Flat.
They are the same note.

Interval Exception: the BC-EF-Rule

A special rule is the BC-EF-Rule: there are no enharmonic notes between B and C and E and F.

The chromatic scale underlining the BC-EF rule.

Scale Formulas

Scales are found using patterns of whole and half steps.

W = Whole Step
H = Half Step

Major Scale

W W H W W W H

The most commonly used Western music scale. Also called Ionian mode.

The A, C and G Major scales.

Natural Minor Scale

W H W W H W W

Also called Aeolian mode.

The A, C and G Natural Minor scales.

Diminished Scale

W H W H W H W H

A whole step / half step pattern.

The A, C and G Diminished scales.

incoming(1) | circle of fifths