# Tag Info

6

All intervals can be turned upside down.(Called inverted). Thus a C-E as a major third, when played E-C becomes a minor sixth. There is a 'rule of nine'.Minors become majors, majors become minors, augmenteds become diminisheds, etc. The exceptions are the octaves, 4ths and 5ths. (Unison doesn't count !) Those do not change their identities. A 4th of C-F ...

4

There are four types of perfect interval: perfect unison, perfect fourth, perfect fifth, and perfect octave. These can be thought of as belonging to two groups. In the first group, all intervals of a unison or an octave are called perfect because the note is not changed. An octave is twice (or half) the frequency of the first note. The second group ...

3

"Is there a solid definition of perfect intervals, lying around somewhere I just can't find?" Yes. A "perfect" interval is an interval that is not one of minor, major, diminished, augmented.

2

Perfect intervals are the ones that don't have two forms: major and minor. C Db D Eb E F F# G Ab A Bb B C root minor major minor major perfect tritone perfect minor major minor major octave 2nd 2nd 3rd 3rd 4th aug/dim 5th 6th 6th 7th 7th ...

1

All the rest have answered in terms of high-level music theory concepts, but I think it can be interesting to look at the intervals as raw coefficients instead. Harmonic intervals between notes are the intervals that can be expressed with simple rational numbers, where a "simple" rational number is one with a small amount of small prime factors. For ...

Only top voted, non community-wiki answers of a minimum length are eligible