An interval describes the distance between any two notes. The distance is measured from the lower note to the upper note using the major scale constructed on the lower note as the measuring stick.
This post will define an interval’s two components — quantity and quality — and provide examples of diatonic intervals, which are intervals that occur naturally within a major scale.
It will also provide common fingerings for each interval, along with instruction on how to play them on a guitar with any root note.
Components
An interval contains two components: a quantity and a quality.
The interval quantity counts the number of scale steps between the two notes and is represented by a number.
The interval quality describes the exact size of the interval — measured in half steps — and is represented by one of the following names:
- Perfect.
- Major.
- Minor.
- Diminished.
- Augmented.
Interval Quantity
The interval quantity is the number of scale steps between the two notes.
To determine an interval’s quantity, start with the lower note and count the number of scale steps between the two notes, including both notes in the count through the musical alphabet.
For example, the distance between a C (the first note in a C major scale) and a D (the second note) is a second because the interval contains two scale steps — C and D (fig.1).
Fig.1
The distance between a C and an E (the third note in a C major scale) is a third because the interval contains three scale steps — C, D and E (fig.2).
Fig.2
The distance between a C and an F (the fourth note in a C major scale) is a fourth because the interval contains four scale steps — C, D, E and F (fig.3).
Fig.3
The distance between a C and the remaining notes in a C major scale is measured the same way:
- The distance between a C and a G (the fifth note) is a fifth.
- The distance between a C and an A (the sixth note) is a sixth.
- The distance between a C and a B (the seventh note) is a seventh.
The distance between a note and the next highest note with the same name (C and the next highest C) is called an octave (the distance of eight scale steps).
And two notes of the exact same pitch are called a unison (the distance of one scale step).
All of the intervals diatonic to a C major scale are shown in fig.4.
Fig.4
Diatonic Intervals
A diatonic interval is an interval that occurs naturally within a major scale.
All of the intervals analyzed above and shown in fig.4 are diatonic intervals because they all occur naturally within a C major scale.
In other words, all of the notes contained in the intervals are diatonic to a C major scale; the intervals contain no sharps or flats.
Interval Quality
The interval quality measures the exact size of an interval. It is defined by the number of half steps between the two notes and is represented by a name.
An interval can be perfect, major, minor, diminished or augmented.
Diatonic intervals are perfect or major.
Perfect Intervals
A perfect interval contains two notes that are found in each other’s major scales.
In any given major scale, the perfect intervals are the unisons, fourths, fifths and octaves.
Perfect Unisons
A perfect unison contains two notes of the exact same pitch.
The distance between a C and another C of the exact same pitch is a perfect unison (fig.5a).
The interval contains one scale step and no half steps between the notes.
Perfect Fourths
The distance between a C and an F is a perfect fourth (fig.5b).
The interval contains four scale steps and five half steps between the notes.
Perfect Fifths
The distance between a C and a G is a perfect fifth (fig.5c).
The interval contains five scale steps and seven half steps between the notes.
Perfect Octaves
The distance between a C and the next highest C is a perfect octave (fig.5d).
The interval contains eight scale steps and 12 half steps between the notes.
Fig.5
Major Intervals
In a major interval, the upper note is found in the major scale of the lower note but the lower note is not found within the major scale of the upper note.
In any given major scale, the major intervals are the seconds, thirds, sixths and sevenths.
Major Seconds
The distance between a C and a D is a major second (fig.6a).
The interval contains two scale steps and two half steps between the notes.
Major Thirds
The distance between a C and an E is a major third (fig.6b).
The interval contains three scale steps and four half steps between the notes.
Major Sixths
The distance between a C and an A is a major sixth (fig.6c).
The interval contains six scale steps and nine half steps between the notes.
Major Sevenths
The distance between a C and a B is a major seventh (fig.6d).
The interval contains seven scale steps and 11 half steps between the notes.
Fig.6
All Eight Diatonic Intervals
All of the intervals diatonic to a C major scale are shown in fig.7.
Fig.7
Diatonic Intervals on a Guitar
An interval can be played harmonically on any two strings.
The interval shapes and examples shown in this post are all played on strings five and six (except for the perfect octaves played on strings four and six).
These same shapes will work on any two adjacent strings except for strings two and three. The interval shapes for the second and third strings are different because of the way a guitar is tuned.
Perfect Unisons
The diagram shown in fig.8a illustrates a perfect unison.
Fig.8b provides the fingering to play the interval.
Fig.8
To play two C’s of the exact same pitch:
- Place your fourth finger on the C on the sixth string, eighth fret (fig.9a).
- Place your first finger on the C on the fifth string, third fret.
To play two A’s of the exact same pitch:
- Place your fourth finger (or any other finger) on the A on the sixth string, fifth fret (fig.9b).
- Play the open fifth string A.
Major Seconds
The diagram in fig.10a illustrates the relationship between any given note and the note a major second above it on a guitar.
Fig.10b provides the fingering to play the interval.
Fig.10
To play a C and the note a major second above it:
- Place your fourth finger on the C on the sixth string, eighth fret (fig.11a).
- Place your first finger on the fifth string, fifth fret — D.
So D is a major second above C.
To play an A and the note a major second above it:
- Place your fourth finger on the A on the sixth string, fifth fret (fig.11b).
- Place your first finger on the fifth string, second fret — B.
So B is a major second above A.
Fig.11
Major Thirds
The diagram shown in fig.12a illustrates the relationship between any given note and the note a major third above it on a guitar.
Fig.12b provides the fingering to play the interval.
Fig.12
To play a C and the note a major third above it:
- Place your second finger on the C on the sixth string, eighth fret (fig.13a).
- Place your first finger on the fifth string, seventh fret — E.
So E is a major third above C.
To play an A and the note a major third above it:
- Place your second finger on the A on the sixth string, fifth fret (fig.13b).
- Place your first finger on the fifth string, fourth fret — C#.
So C# is a major third above A.
Fig.13
Perfect Fourths
The diagram shown in fig.14a illustrates the relationship between any given note and the note a perfect fourth above it on a guitar.
Fig.14b provides the fingering to play the interval.
Fig.14
To play a C and the note a perfect fourth above it:
- Place your first finger on the C on the sixth string, eighth fret (fig.15a).
- Place your first finger on the fifth string, eighth fret — F.
So F is a perfect fourth above C.
To play an A and the note a perfect fourth above it:
- Place your first finger on the A on the sixth string, fifth fret (fig.15b).
- Place your first finger on the fifth string, fifth fret — D.
So D is a perfect fourth above A.
Fig.15
Perfect Fifths
The diagram shown in fig.16a illustrates the relationship between any given note and the note a perfect fifth above it on a guitar.
Fig.16b provides the fingering to play the interval.
Fig.16
To play a C and the note a perfect fifth above it:
- Place your first finger on the C on the sixth string, eighth fret (fig.17a).
- Place your fourth finger on the fifth string, 10th fret — G.
So G is a perfect fifth above C.
To play an A and the note a perfect fifth above it:
- Place your first finger on the A on the sixth string, fifth fret (fig.17b).
- Place your fourth finger on the fifth string, seventh fret — E.
So E is a perfect fifth above A.
Fig.17
Major Sixths
The diagram shown in fig.18a illustrates the relationship between any given note and the note a major sixth above it on a guitar.
Fig.18b provides the fingering to play the interval.
Fig.18
To play a C and the note a major sixth above it:
- Place your first finger on the C on the sixth string, eighth fret (fig.19a).
- Place your fourth finger on the fifth string, 12th fret — A.
So A is a major sixth above C.
To play an A and the note a major sixth above it:
- Place your first finger on the A on the sixth string, fifth fret (fig.19b).
- Place your fourth finger on the fifth string, ninth fret — F#.
So F# is a major sixth above A.
Fig.19
Major Sevenths
The diagram shown in fig.20a illustrates the relationship between any given note and the note a major seventh above it on a guitar.
Fig.20b provides the fingering to play the interval.
Fig.20
To play a C and the note a major seventh above it:
- Place your first finger on the C on the sixth string, eighth fret (fig.21a).
- Place your fourth finger on the fifth string, 14th fret — B.
So B is a major seventh above C.
To play an A and the note a major seventh above it:
- Place your first finger on the A on the sixth string, fifth fret (fig.21b).
- Place your fourth finger on the fifth string, 11th fret — G#.
So G# is a major seventh above A.
Fig.21
Perfect Octaves
The diagram shown in fig.22a illustrates the relationship between any given note and the note a perfect octave above it on a guitar.
Fig.22b provides the fingering to play the interval.
Fig.22
To play a C and the C an octave above it:
- Place your first finger on the C on the sixth string, eighth fret (fig.23a).
- Place your fourth finger on the fourth string, 10th fret — C.
To play an A and the A an octave above it:
- Place your first finger on the A on the sixth string, fifth fret (fig.23b).
- Place your fourth finger on the fourth string, seventh fret — A.
Fig.23
Melodic vs Harmonic Intervals
An interval can be melodic or harmonic.
In a melodic interval, the two notes are played successively, one after the other. In a harmonic interval, the two notes are played simultaneously.
A harmonic interval is also called a diad or double stop.
Diatonic Intervals Sounds and Qualities
Each interval evokes its own quality, sound or feeling. Some intervals are consonant — the notes blend well when played together. And some are dissonant — the notes tend to clash with one another.
Perfect intervals are the most consonant, followed by major thirds and major sixths. Major seconds and major sevenths are considered dissonant.
Related Posts
- Harmonizing the Major Scale I: Triads.
- Intervals II: Altered Intervals.
- Intervals III: Inverted Intervals.
- Diatonic Double Stops.