- This topic has 3 replies, 3 voices, and was last updated 3 years, 5 months ago by
.
-
Posts
-
-
Intervals really are the foundations of music theory. But like many things in music theory, they seem awfully confusing. So let’s break that down.
An interval is simply the distance between two notes.
It can be ascending (going up from C to G for example) or descending (going down from C to G).In theory, all the intervals can be defined in terms of whole and half steps; however, we need to distinguish between diatonic half steps and chromatic half steps, and the definitions of the intervals are hard to remember.
Fortunately, there is a much easier way.In order to be able to completely identify an interval, you need to be able to write down the major scale whose tonic is the lowest note of the interval.
For example, if you try to identify the interval Eb – A, you first need to write de Eb major scale: Eb F G Ab Bb C D Eb1. Type of interval
The type of an interval is the total number of notes it comprises.
For example, Eb – A is a fourth (4th) because there are four notes going from Eb to A (Eb, F, G, A).
Similarly, Db – A# is a fifth (5th) because there are five notes (Db, E, F, G, A#)2. Quality of an interval
In the major scale, the 4th, the 5th and the octave (8th) are perfect.
– if you raise a perfect interval by a half step you get an augmented 4th, 5th or octave.
– if you flatten a perfect interval, you get a diminished 4th, 5th or octave.In the major scale, the 2nd, 3rd, 6th and 7th are major.
– if you raise a major interval by a half step you get an augmented 2nd, 3rd, 6th or 7th.
– if you flatten a major interval, you get a minor 2nd, 3rd, 6th or 7th.If you flatten a minor interval, you get a diminished interval.
That’s it!
The attached PNG document summarizes all this graphically.Intervals can be larger than an octave: the 9th is a 2nd an octave higher, the 11th is a 4th an octave higher, etc.
So, what is Eb – A (ascending)?
We know that in the Eb major scale Eb – Ab is a perfect 4th; therefore Eb – A is an augmented 4th.
The descending interval Eb – A is a diminished 5th.Other example: what is the ascending interval D – Bb ?
Let’s first write the D major scale: D E F# G A B C# D.
In that scale, D – B is a major 6th; therefore, D – Bb is minor 6th.Final word of caution.
The interval C – F# is an augmented 4th, but C – Gb is a diminished 5th! This is because you count 4 notes from C to F, but five notes from C to G. Sound wise, these two intervals are of course identical because Gb and F# are enharmonic notations for the same pitch.
Similarly, C – E is a major 3rd, but C – Fb is a diminished 4th. -
-
-
-
- You must be logged in to reply to this topic.
