# Why do intervals have such complicated names?

In a ruler I have 1cm, 2cm, 3cm, 4cm, etc.
Why isn't there in music: 1st, 2st, 3st, 4st, etc. (where st = semitone)

But instead we have:

Minor second, Major second, Minor third, Major third, Perfect fourth, Perfect fifth, Minor sixth, Major sixth, etc..

Why are they called with such long complicated names? (major,minor,perfect), and why do they add an additional semitone in the name? (example: we say "minor second" but it's just 1-semitone.. so shouldn't it be called a "minor first". or just call it a first. or just a 1st :))

• The major / minor / perfect is a useful indication though I feel that the second is misnamed as the second in a minor scale is major. If I were to object, it would that the numbers are wrong: they should all be one less. A third plus a third is a fifth and not a sixth as you might expect. Apr 26, 2017 at 16:28
• What's the additional semitone in the name? Complicated with only two words?
– Tim
Apr 26, 2017 at 16:33
• If you want to count distance, then you can of course use semitones -- and you will be understood. Intervals are describing relationships.
– user28
Apr 26, 2017 at 17:52
• @badjohn: I see what you mean about the quality of the interval, but the central terms are major (for 2nd, 3rd, 6th, and 7th) and perfect (for 4th, 5th, and octave). Minor is always one half-step shy of major, diminished is one half-step shy of minor or perfect, and augmented is one half-step over major or perfect. Apr 26, 2017 at 23:14
• @badjohn: As for the numbers, I'm sure that's historical. The fact that they're given ordinal names is a clue: In C Major, D is the second note, E is the third note, etc., so C-D is a second, C-E is a third, etc. Apr 26, 2017 at 23:15