The following table shows the types of intervals it is possible to represent in traditional notation and in a chromatic staff notation. It illustrates how the addition of key signatures and accidental symbols each allow for greater specificity in the representation of (enharmonic) intervals.
A chromatic staff notation system that has alternative key signatures and accidental signs (that allow for differentiation between enharmonically equivalent notes like C# and Db) can represent the same set of interval types that are found in traditional notation.
Numbers in parentheses indicate semitones. Double sharps and double flats are not included, only single sharps and single flats. See also Enharmonic Intervals on Wikipedia
| Just the Staff (No Key Signature or Accidental Signs) |
Staff + Key Signature (No Accidental Signs) |
Staff + Key Signature + Accidental Signs (Sharps and Flats) |
|
|---|---|---|---|
| Traditional Notation | Chromatic Staff Notation | Traditional Notation and Chromatic Staff Notation limited to only notes in the current key |
Traditional and Chromatic Staff Notation |
| 7 diatonic notes per octave | 12 chromatic notes per octave | 7 diatonic notes per octave | 21 chromatic notes per octave |
| 8 Interval Types | 12 Interval Types | 13 Interval Types (Diatonic Intervals) |
26 Interval Types (Chromatic Intervals) |
| Unison (0) | 0 Semitones | Perfect Unison (0) | Perfect Unison (0) |
| Diminished second (0) | |||
| Second (1-2) | 1 Semitone | Minor second (1) | Augmented unison (1) |
| Minor second (1) | |||
| 2 Semitones | Major second (2) | Major second (2) | |
| Diminished third (2) | |||
| Third (3-4) | 3 Semitones | Minor third (3) | Augmented second (3) |
| Minor third (3) | |||
| 4 Semitones | Major third (4) | Major third (4) | |
| Diminished fourth (4) | |||
| Fourth (5-6) | 5 Semitones | Perfect fourth (5) | Augmented third (5) |
| Perfect fourth (5) | |||
| 6 Semitones | Augmented fourth (6) | Augmented fourth (6) |
|
| Fifth (6-7) | Diminished fifth (6) | Diminished fifth (6) | |
| 7 Semitones | Perfect fifth (7) | Perfect fifth (7) | |
| Diminished sixth (7) | |||
| Sixth (8-9) | 8 Semitones | Minor sixth (8) | Augmented fifth (8) |
| Minor sixth (8) | |||
| 9 Semitones | Major sixth (9) | Major sixth (9) | |
| Diminished seventh (9) | |||
| Seventh (10-11) | 10 Semitones | Minor seventh (10) | Augmented sixth (10) |
| Minor seventh (10) | |||
| 11 Semitones | Major seventh (11) | Major seventh (11) | |
| Diminished octave (11) | |||
| Octave (12) | 12 Semitones | Perfect octave (12) | Augmented seventh (12) |
| Perfect octave (12) | |||