There are faster and more reliable methods of identifying and constructing intervals than counting whole tones and semitones. Here, we will explore some of these methods. Below is a brief description of each method:
- Scales: If you know the major and minor scales on your instrument, you can use them to identify intervals. For example, the interval from D to A is a perfect fifth because D is the first note of the D major scale and A is the fifth note of the D minor scale. If the A is sharp, the interval becomes larger and is considered augmented. If A is flat, the interval becomes smaller and is called diminished.
- Chords: If you know the basic chords (or arpeggios) on your instrument, you can use them to identify intervals. For example, there is a perfect fifth between D and A because they are the root and fifth of the D major and D minor chords, respectively. If the A is sharp, the interval becomes larger and is considered augmented. If A is flat, the interval becomes smaller and is called diminished.
- Inversion — This method is useful for working with large intervals, such as sixths and sevenths, since they become thirds and seconds after inversion. Isn't it easier to identify a second than a seventh? See Inversion and Identifying by Using Inversions for more information.
Scales: from the first note to the second note of any major or minor scale, we have a major second.
Chords: from the root of any major chord to its third, we have a major third. In the case of minor chords, the third is minor.
Scales: from the first note to the third note of any major scale, we have a major third. From the first note to the third note of any minor scale, we have a minor third.
Scales: from the first to the fourth note of any major or minor scale, we have a perfect fourth.
Chords: from the root to the fifth of any major or minor chord, we have a perfect fifth.
Scales: from the first to the fifth note of any major or minor scale, we have a perfect fifth.
Inversion: a sixth inverts into a third. We invert an interval by raising its lower note one octave. Major intervals become minor, minor intervals major, perfect intervals remain perfect, augmented intervals become diminished and diminished intervals become augmented.
Scales: from the first note to the sixth note of any major scale, we have a major sixth. In minor scales the sixth from the first to the sixth note is minor.
Chords: from the root to the seventh of any major seventh chord, we have a major seventh. From the root to the seventh of any dominant seventh chord, we have a minor seventh.
Scales: from the first note to the seventh note of any major scale, we have a major seventh. In minor natural scales, the seventh from the first to the seventh note is minor.
Inversion: a seventh inverts into a second. We invert an interval by raising its lower note one octave. Major intervals become minor, minor intervals major, perfect intervals remain perfect, augmented intervals become diminished and diminished intervals become augmented.
