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LearnMusicTheory.net High-Yield Music Theory, Vol. 1: Music Theory Fundamentals
Section 3.1
INTRODUCTION
TO
INTERVALS
Interval
definition
An interval is the pitch distance (high-low distance) between two notes.
Interval names have two parts:
1. The general category of the interval, based on counting the number of
letter names using the starting letter name as number one; and
2. The quality of the interval, related to how many half steps are between
the notes.
Major and perfect
intervals
Major and perfect quality intervals match the notes of a major scale,
starting from the first note of the scale up. Seconds, thirds, sixths, and
sevenths can be major in quality, but never perfect. Unisons, fourths,
fifths, and octaves (“8ves”) can be perfect in quality, but never major.
&
C major scale with scale steps numbered:
w
w
w
w
w
w
w
6
7
w
I
I
I
I
I
I
I
I
w
w
w
& w w ww ww ww ww w
w
w
1
2
3
1 - 1
1-2
1-3
(2)
(4)
Half steps: (0)
Major Major
Perfect
3nd
Unison (PU) 2nd
Minor intervals
4
5
8
1-4
1-5
1-6
1- 7
1- 8
(5)
(7)
(9)
(11)
(12)
Perfect Perfect Major Major Perfect
4th
5th
6th
7th Octave (8ve)
Minor intervals are one half step smaller than major intervals, keeping the
same letter names. Only intervals that can be major are able to become
minor: seconds, thirds, sixths, and sevenths only.
Seconds:
Thirds:
& w bw
Minor second
& w nw
& w bw
& w nw
& w bw
& w nw
& w bw
& w nw
Major second
{
Sixths:
Minor sixth
{
Major sixth
Major third
{
Sevenths:
Minor third
Minor seventh
{
Major seventh
Chapter 3: Intervals and Transposition
Diminished
Augmented
43
Diminished intervals are one half step smaller than minor or perfect
intervals, keeping the same letter names. Augmented intervals are one half
step larger than major or perfect intervals, keeping the same letter names.
Thirds (seconds, sixths, and sevenths are similar):
& w ∫w
Diminished third
{
& w bw
Minor third
{
& w nw
Major third
_
& w #w
Augmented third
Fourths (unisons, fifths, and octaves are similar):
& w
bw
Diminished fourth
Consonant
intervals
Perfect, imperfect
consonances
Dissonant
intervals
Perfect fourth
Simple and
compound
intervals
&
{
w
nw
Perfect fourth
_
& w
#w
Augmented fourth
Consonant intervals are intervals that sound more stable because of the
closer relationship between the physical vibration patterns of the notes.
The closest relationships (and therefore the most stable intervals) are the
perfect consonances: perfect unison, perfect fifth, and perfect octave. The
imperfect consonances are major and minor thirds and sixths. They are not
as stable as perfect consonances, but more stable than dissonances.
The dissonant intervals are seconds and sevenths as well as all diminished
and augmented intervals. The notes in dissonant intervals have physical
vibration patterns that are relatively unrelated to one another and are
therefore unstable when compared to consonances. The perfect fourth is
sometimes considered a consonance and sometimes a dissonance,
depending on style and musical context.
Simple intervals are an octave or smaller. Compound intervals are larger
than an octave. Compound intervals use the same quality names as their
simple counterparts (major, perfect, etc.). To convert from simple to
compound, add 7. Example: 2nd + 8ve = 9th since 2 + 7 = 9.
Perfect 8ve
Major 10th
Perfect 12th
Major 14th
Major 9th
Perfect 11th
Major 13th
Perfect 15th
& w
w
8ve
w
w
w
w
w
w
w
w
w
w
w
w
w
w
8ve+2nd 8ve+3rd 8ve+4th 8ve+5th 8ve+6th 8ve+7th 8ve+8ve