In music, an interval is the distance between two pitches (also called tones
or notes).
Types
An interval within the span of an octave is called a simple interval
(ex.1).
An interval with a span more than an octave is called a compound
interval (ex.2).
An interval comprised of successive pitches (horizontal) is called a melodic
interval (ex.3).
An interval comprised of simultaneous pitches (vertical) is called a harmonic
interval (ex.4).
Intervals can be described as general
intervals (such as thirds, fourths or fifths) or as specific intervals (such
as major thirds, perfect fourths or diminished fifths) (ex.5).
A general interval can be gained by counting from one pitch to the other (either
up or down) with the first pitch as one (1) and counting every line and space in between (e.g. C to G would be
C-D-E-F-G or 1-2-3-4-5 or a fifth).
To gain a specific interval, one must count every semi-tone (half step) between
two pitches (e.g. C to G would be C-C#, C#-D, D-D#, D#-E, E-F, F-F#, F#-G or seven half-steps or a perfect fifth) (ex.6).
In western music, the smallest interval is a semi-tone (also called a half-tone
or minor second). The following chart gives the names of all intervals from a
unison (or prime) up to a major 9th.
Enharmonic
Tones
Enharmonic tones
are tones which are spelled differently but sound the same (e.g. C# and Db). A composer usually chooses one over the
other with respect to the key of the music (e.g. C# would most likely be used if the key signature contained sharps and similarly
Db would most likely be used if the key signature contained flats). An exception to this rule is in chromatic scales
where sharps are most often used for ascending scales and flats are most often used for descending scales.
Chart
of Basic Intervals (ex.7)
Number of Half Steps Interval
Name Example
0 perfect prime (P1) C
to C
1 augmented prime
(A1) C to C#
1
minor second (m2) C to Db
2
major second (M2) C to D
3 augmented
second (A2) C to D#
3
minor third (m3) C
to Eb
4
major third (M3) C
to E
4 diminished
fourth (d4) C to Fb
5 perfect
fourth (P4) C to F
6 augmented
fourth (A4) C to F#
6 diminished
fifth (d5) C to Gb
7
perfect fifth (P5) C
to G
8
augmented fifth (A5) C to G#
8 minor
sixth (m6) C
to Ab
9
major sixth (M6) C
to A
9 diminished
7th (d7th) C to Bbb
10 augmented
6th (A6th) C to A#
10 minor
seventh (m7) C to Bb
11 major
seventh (M7) C to B
11 diminished
octave (d8) C to Cb
12
perfect octave (P8) C to C
13 augmented
octave (A8) C to C#
13
minor ninth (m9) C
to Db
14
major ninth (M9) C
to D
Classification of Intervals (quality
of sound)
Perfect consonances have a pure or "hollow" sound
and generally sound well together and are easy on the ear. Examples are perfect octaves, perfect fifths and perfect
fourths and perfect unisons (ex.8).
Imperfect consonances have a more complex sound
but are still pleasant sounding to the ear. Examples are major and minor thirds and major and minor sixths (ex.9).
Dissonances do not sound as well together
and are less pleasing to the ear. Examples are minor seconds and major sevenths (which have a jarring or harsh quality),
major seconds and minor sevenths (which are less harsh in quality) and augmented fourths and diminished fifths (also called
"tritones" - which have a static or sometimes unstable quality) (ex.10).
Suggested Assignment 1 - Interval Identification
Take any piece of music on which you are currently
working, count the number of half-steps between any two adjacent pitches, then find the corresponding interval from the chart
above and pencil in the appropriate abreviation for that interval. Continue this process for each successive pair
of pitches until you have gained some skill in identifying the various intervals.
Suggested Assignment 2 - Interval Construction
Take a piece of staff paper and draw a treble clef at the beginning
of each staff. On the first staff write out each interval found in the above chart. Use wholenotes for each tone
and use accidentals as needed. Write the pitches either side-by-side (melodic) or one over the other (harmonic). Write
the appropriate abbreviation underneath each interval. Then continue this process on successive staves by starting
each interval on different pitches.
Suggested Assignment 3 - Ear Training
1
Play these different intervals on your instrument or the piano and
listen to their basic qualities. Try to distinguish the difference between any two intervals (e.g. a major
and a minor third or a fourth or a fifth). If you are using a piano, play the intervals harmonically as well as
melodically. This will improve your ear and ready you for the next chapter which deals with chords.
Suggested Assignment 4 - Ear Training
2
Get with a fellow musician and practice listening to all the different
intervals. Have one person play an interval on the piano while the other tries to decide what interval is being played.
Then trade places so that each person gets a chance to improve his/her musical ear. It's best to start with the perfect
consonant intervals at first (octaves, fifths and fourths), then the imperfect consonances (thirds and sixths) and finally
the dissonant intervals (seconds, sevenths and tritones).
Hint: Each interval can initially be identified with a well-known
melody (e.g. a major sixth is the first two pitches of TV's "NBC" theme, a perfect fourth is the first two pitches of "Here
Comes the Bride", and an octave is the first two pitches of "Somewhere, Over the Rainbow", etc.). See if you can discover
a well-known melody to help you identify each interval.
