- The distance between two notes/pitches played together is called, harmonic interval.
- Intervals are named by size and quality.
- Interval Quality: The possible qualities are major (M), minor (m), perfect (P), diminished (º) and augmented (+).
- Interval Size: count the note names between the two notes given. (see table below)
- Intervals that are 2, 3, 6, or 7 in size can be major, minor, diminished or augmented. These intervals can never be perfect.
- Intervals that are 1, 4, 5, or 8 in size can be perfect, diminished or augmented. These intervals can never be major or minor.
- The figure below shows the simple intervals from C to any notes above.
Compound intervals are intervals larger than an octave. (Above 6 tones). The first ligne below shows the number of semitones. From a to x are the figure references shown in the tables below. Compound intervals are functionally the same as the corresponding simple intervals (those an octave or less in size). Thus, a 9th is a compound 2nd (M9), an 11th is a compound 4th (P11) and a 13th is compound 6th (M13).
Consonance and Dissonance
- Consonant intervals are those intervals that sound stable and usually pleasant. (P1, P8, P5, M3, m3, M6, m6.)
- Dissonant intervals are those that sound harsh and unstable, they feel as if they want to resolve: (M2, m2, M7, m7, augmented and diminished intervals.)
- The P1, P8, and P5 are known as perfect consonances.
- The M3, m3, M6 and m6 are known as the imperfect consonance.
According to Hindemith and generally speaking, the consonant intervals excel in harmonic power, the dissonant intervals in melodic power, whereas the tritone is considered apart, as possessing specifically, neither harmonic nor melodic significance. The term root is applied not only to chords but also to intervals. In the perfect fifth, major and minor thirds, and major and minor seventh, the root tone of the interval is the lower tone; in the perfect fourth, major and minor sixths, and major and minor seconds, the root tone is the upper tone of the interval. The fundamental of a chord is found by first selecting the "best" interval between any two tones of the chord, the intervals being arranged in a series to decreasing value from the perfect fifth to the major seventh.
You can listen to the simple intervals from C to C to hear how they sound like.