Learning how to name intervals in music has abounding acceptance in a accompaniment of frustration.
Intervals ambit from the actual simple central above scales, to the added complicated if we accord with bright addendum and to the acutely abreast absurd to plan out, if bifold sharps and flats appear into play. To be able to name intervals you charge to accept half-tones (semi-tones, bisected steps) and whole tones, because the ambit amid 2 addendum is counted in 1/2 steps. It is aswell actual accessible to apperceive the amphitheater of 5ths diagram.
Interval names abide of a number (second, fourth etc.) and a modifier (unison, minor, major, perfect, diminished, aggrandized & octave).
Finding the amount is simple in a lot of cases, alive out the modifier can get a bit added tricky.
Let's alpha with the simple ones:
The 8 Simple Diatonic Intervals:
The are abstinent in every key from the analeptic (root note) to the added 7 addendum in anniversary scale.
Ex: key of C:
C - C = Absolute Accord (0 semi-tones)
C - D = Above Additional (2 half-tones)
C - E = Above Third (4 semi-tones)
C - F = Absolute Fourth (5 1/2 steps)
C - G = Absolute Fifth (7 semi-tones)
C - A = Above Sixth (9 half-tones)
C - B = Above Seventh (11 semi-tones)
C - C = Absolute Octave (12 1/2 steps
No amount what key you're in, unisons, fourths, fifths and octaves are consistently Perfect and seconds, thirds, sixths and sevenths are consistently Major. So far, so good.
Now, of advance there are added intervals accessible in every above key, 48 in fact, amid any above calibration agenda and every added above calibration note. Here is area the added modifiers appear into play.
We acquisition out that:
Seconds can aswell be accessory (ex: E - F & B - C) (1 semi-tone)
Thirds can aswell be accessory (ex: D - F, E - G, A - C & B - D) (3 semi-tones)
Fourths can be Aggrandized (ex: F - B) (6 half-tones)
Fifths can be Beneath (ex: B - F) (also 6 semi-tones)
Sixths can be Accessory (ex: E - C, A - F & B - G) (8 1/2 steps)
Sevenths can be Accessory (ex: D - C, E - D, G - F, A - G & B - A) (10 half-tones)
We can sum up that central anniversary above scale, 2nd, 3rd, 6th and 7th intervals are MAJOR or MINOR, while unison, 4th, 5th & octave intervals are PERFECT, AUGMENTED (+ 1/2 step) or DIMINISHED (- 1/2 step).
Thankfully the art of how to name any breach does not get abundant added complicated than discussed so far. We already apperceive the numbers and accessible modifiers but if it comes to the endless bright breach possibilities there is one added ambit we accept to cope with:
2nds, 3rds, 6ths and 7ths can aswell be Beneath or Augmented. That's it!
All that charcoal is to summarise:
- Unison, Fourth, Fifth and Octave Intervals are either Perfect, Beneath or Augmented.
- Second, Third, Sixth and Seventh Intervals can be Above or Accessory and aswell Beneath or Augmented.
For intervals that are added than an octave, the rules are simple: Treat ninths like you would a second, tenths like thirds, elevenths like fourths etc.
By far the quickest way to apprentice the name of intervals is to become absolutely accustomed with the above scales and their modes and accept the amphitheater of fifths explained thoroughly.