An interval in music is the distance in pitch between two notes. The interval is counted from the lower note to the higher one, with the lower counted as 1. Intervals can be named generally by merely counting upwards (by going forwards using the letters of the musical alphabet) from one note to the other, inclusively. For example, from C to E is a third (C to C is 1, or more commonly and elegantly, a unison, C to D is a second and finally, c to E is a third.) Intervals are named by the number of the upper note (2nds, 3rds, etc. ) but there are two exceptions to this. The interval between notes that are identical is called UNISON (also called a PRIME INTERVAL); the interval of an 8th is called an OCTAVE.
Melodic and Harmonic Intervals
Intervals are called Melodic Intervals when they are sounded separately and Harmonic Intervals when they are sounded together. When studying chords we talk about harmonic intervals. When melodies are played, we study melodic intervals.
Mary Had a Little Lamb = E-D-C-D-E-E-E is a melodic interval.
C Major Chord = C + E + G played together is a harmonic interval.
3rd and 5th intervals make up the major chord. A lowered 3rd interval (minor interval) and 5th interval make up the minor chord.
Perfect and Major Intervals
The interval between the keynote of a major scale and the unison, 4th, 5th, or octave of that scale is called a Perfect Interval.
For example, the difference from C to G (in a C major scale) is called a Perfect 5th. The difference from C to F is called a Perfect 4th. The 8th note of the scale is referred to as the Perfect Octave. The difference between the same note is called the Perfect Unison.
The interval between the keynote of a major scale and the 2nd, 3rd, 6th or 7th of that scale is called a Major Interval.
For example, the difference from c to c (in a C major scale) is called a Major 2nd. The difference from C to E is called a Major 3rd. The difference from C to A is called a Major 6th and the difference from C to B is called a Major 7th.
Minor Intervals
When the interval between two notes of a major interval (2nd, 3rd, 6th or 7th) is decreased by a half step, they become Minor Intervals.
For example, a major 3rd becomes a minor third when decreased by a half step. In a C major scale, the major third interval is from C to E. Changing the major third to a minor third would simply mean lowering the E to E flat. A minor 2nd would be D flat instead of D. A minor 6th would be A flat instead of A. The minor 7th interval would include B flat instead of B.
Only Major intervals may be made into minor intervals. Perfect intervals may not (for example, a minor perfect does not exist).
Augmented and Diminished Intervals
The word augmented means “made larger.” When a perfect or major interval is made larger by a half step, it becomes an Augmented Interval. For example, a perfect 5th can become an augmented 5th by raising the 5th one half step.
In a C major scale, the perfect 5th is the interval from C to G. By simply raising G to G#, the interval has been expanded, which makes it an Augmented 5th.
The word diminished means “made smaller.” When a perfect or minor interval is made smaller by a half step, it becomes a Diminished Interval. For example, a perfect 4th can become a diminished 4th by lowering the 4th a half step.
In the C Major scale, G is the perfect 5th. By simply lowering G to Gb, it has been made the diminished 5th.
Chromatic Interval
When the keynote and the upper note of an interval are not from the same major scale, it is called a Chromatic Interval. Minor, diminished and augmented intervals are always chromatic intervals in major keys.
Summary:
What is an interval?
Unison (Prime Interval) and Octave
Melodic/Harmonic Intervals
Perfect Unison, 4th, 5th and Perfect Octave
Major 2nd, 3rd, 6th and 7th
Minor Intervals
Augmented and diminished Intervals
Chromatic Intervals
Now we’ve laid some groundwork for you to understand chords.
Get ready, here comes some more chords!
