Music Theory Reference – Chords, Scales & Intervals

Intervals
Technical name per semitone distance
Interval Technical name
1 semitone minor second
2 semitones major second
3 semitones minor third
4 semitones major third
5 semitones perfect fourth
6 semitones tritone
Interval Technical name
7 semitones perfect fifth
8 semitones minor sixth
9 semitones major sixth
10 semitones minor seventh
11 semitones major seventh
12 semitones octave
Basic Chords
Common triads & suspended chords
  1. major triads
  2. minor triads
  3. diminished triads
  4. augmented triads
  5. suspended second chords
  6. suspended fourth chords
Scales
Most-used scale families
  1. major scales
  2. natural minor scales
  3. harmonic minor scales
  4. melodic minor scales
  5. major pentatonic scales
  6. minor pentatonic scales
  7. blues scales
  8. chromatic scales
Seventh Chords
Common seventh chord families
  1. dominant seventh chords
  2. major seventh chords
  3. minor seventh chords
  4. minor major seventh chords
  5. diminished seventh chords
  6. augmented seventh chords
  7. half-diminished seventh chords
  8. augmented major seventh chords
Other Chords
Additional chord types
  1. diminished triads
  2. augmented triads
  3. augmented chords
The names of piano keys
Note that the interval between two adjacent sounds in this table is one semitone horizontally and one octave vertically.
with frequencies: