Overview
This cheat sheet provides an at-a-glance summary of essential music theory elements: keys, scales, modes, notes, chords, intervals, key signatures, and the circle of fifths.
Keys & Scales
- Selecting a key (major or minor) reveals its notes, formula, relative keys, modes, and key signature.
- C Major scale notes: C, D, E, F, G, A, B, C.
- C Major scale formula: 1 2 3 4 5 6 7; steps: whole, whole, half, whole, whole, whole, half.
- Relative minor of C Major: A Minor; relative major of A Minor: C Major.
- Harmonic minor scale has a raised 7th degree for a stronger leading tone.
- Melodic and pentatonic variations exist for major and minor keys.
Modes
- The seven modes derived from the major scale: Ionian, Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian.
- Each mode starts on a different scale degree and produces a unique sequence of intervals.
Scale Degrees & Intervals
- 1-Tonic (C, unison), 2-Supertonic (D, major 2nd), 3-Mediant (E, major 3rd), 4-Subdominant (F, perfect 4th).
- 5-Dominant (G, perfect 5th), 6-Submediant (A, major 6th), 7-Leading Tone (B, major 7th), 8/1-Octave/Tonic (C, perfect 8th).
Chords & Diatonic Harmony
- Diatonic triads in C Major: I (C), ii (Dm), iii (Em), IV (F), V (G), vi (Am), vii° (B diminished).
- Diatonic 7th chords add the 7th note above the root.
- Functional harmony: tonic chords (I, iii, vi), subdominant (IV, ii), dominant (V, vii).
- In minor: tonic (i, III), subdominant (iv, VI, ii), dominant (V, v, VII, vii).
Common C Chords
- Major (C), minor (Cm), diminished (Cdim), augmented (Caug), and their 7th, 6th, 9th, sus2, sus4, and half-diminished forms.
- Chord formulas use scale degree numbers for construction.
Key Signatures & Circle of Fifths
- Order of sharps: F C G D A E B; order of flats: B E A D G C F.
- The circle of fifths shows relationships and key signatures for all major and minor keys.
Chromatic Scale & Solfège
- Chromatic scale: C-C#-D-D#-E-F-F#-G-G#-A-A#-B.
- Solfège syllables: Do, Re, Mi, Fa, So(l), La, Ti, Do.
Symbols & Nomenclature
- Major: M, maj; Minor: m, min, -; Dominant 7th: 7, dom7.
- Diminished: dim; Half-diminished: m7b5; Augmented: aug, +.
- Accidentals: sharp (#), flat (b), natural (â™®), double sharp (x), double flat (bb).
Key Terms & Definitions
- Key — The set of notes defining a musical scale starting from a tonic.
- Scale — An ordered sequence of notes by pitch.
- Mode — A scale pattern starting on a different degree of the parent scale.
- Interval — The pitch distance between two notes.
- Diatonic Chord — A chord built only from notes within a given key.
Action Items / Next Steps
- Review individual scales, chord formulas, and interval charts linked in the cheat sheet.
- Practice identifying key signatures and chord functions.
- Explore the Circle of Fifths and related tools for deeper understanding.