乐理参考 - 和弦、音阶与音程

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:

What you can do on this page

This is a reference page rather than a lesson: the interval table, the chord and scale families, and a playable map of every key with its frequency. Click any key in the map to hear it — the notes are laid out exactly as they sit on the keyboard, one semitone apart horizontally and one octave apart vertically.

Use it as a lookup while you learn. If a song page mentions a major third, the interval table tells you it is four semitones. If you are working on the C major scale, the scale list shows you which family it belongs to and where to go next.

How chords, scales and intervals fit together

A scale is a set of notes, a chord is a few notes from that set played together, and an interval is the distance between any two of them. That is the whole hierarchy: learn the twelve intervals and you can build any scale; learn a scale and you can build every chord that belongs to it.

In C major the practical version is short. The scale is C D E F G A B, the three most useful chords are C, F and G, and the shape that builds each of them is a major third stacked on top of a minor third. Everything else on this page is a variation on that idea.

Using the keyboard map below

The two grids at the bottom of the page show the same keyboard twice: once with note names, once with frequencies in hertz. Each row is one octave, and the rows step down from octave 6 to octave 1.

Middle C is the C in the octave 4 row, and it is the reference point every other note is measured from. Press it, then press the same C one row up, and you hear an octave: twelve semitones, the same note name, twice the frequency.