Intervals

Intervals are sound differences between two notes. We measure how many steps are between two notes, or their distance. Start from a scale's Root note, and any other note is an interval that is steps away.

Major Intervals

Starting from C in the C Major scale:

CDEFGABC
  • D = 2nd note from C (Root).
  •        We name that interval a Major 2nd, or M2.

  • E = 3rd note from C. It's a Major 3rd, or M3.

  • F = 4th note from C, and named a Perfect 4th, or P4.

  • G = 5th note from C, and named a Perfect 5th, or P5.

  • A = 6th note from C, and named a Major 6th, or M6.

  • B = 7th note from C, and named a Major 7th, or M7.

  • C to C is named an octave, which is Perfect, P8.

Intervals have different names based on their sound difference. Name them starting from the lower to the higher note. With scales, it's always the 1st note, the root, that's the lower note. Minor scale intervals are explained later.

The Major steps above, simplified:

  • C (root, Perfect Unison, P1)
  • D (M2)
  • E (M3)
  • F (P4)
  • G (P5)
  • A (M6)
  • B (M7)
  • C (octave, P8)

minor intervals

Now, for the a minor scale (the relative minor - same key signature as C Major):

abcdefga
  • a (P1)
  • b (Major 2nd, or M2)
  • c (minor 3rd, or m3)
  • d (P4)
  • e (P5)
  • f (m6)
  • g (m7)
  • a (P8)

3 / 6 / 7

Notice the difference of interval names, between the Major and minor scales: The 3rd, 6th, and 7th interval names match the type of scale, Major (CDEFGABC) or minor (abcdefga).

ScaleInterval
Major P1 | M2 | M3 | P4 | P5 | M6 | M7 | P8
minor P1 | M2 | m3 | P4 | P5 | m6 | m7 | P8

However, the 2nd note in the minor scale is a Major interval:

  • M: Major 2nd (C to D) 2half steps between
  • m: Major 2nd (a to b)  2half steps between (even though a minor scale)

  • M: Major 3rd (C to E) 4half steps between
  • m: minor 3rd (a to c)  3half steps between

  • M: Major 6th (C to A) 9half steps between
  • m: minor 6th (a to f)  8half steps between

  • M: Major 7th (C to B) 11half steps between
  • m: minor 7th (a to g)  10half steps between

Again, the 2nd interval, whether a Major or minor scale, is a Major 2nd. The half steps remain the same, 2 half steps. But the 3rd, 6th, and 7th intervals, have different names because of different half steps between (Major or minor).

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Next, compare the A Major scale to the a minor parallel scale:

A  B  C#  D  E  F#  G#  A
a   b   c   d   e   f   g   a

Parallel minor scales have the 3rd, 6th, and 7th notes flat from Major scales. So a Major interval becomes a parallel minor when we flat those intervals. Comparing the A Major and minor scale:

  • C# flats to c
  • F# flats to f
  • G# flats to g

...with c,f,g being the minor scale intervals. It's easy now to switch from a Major to a parallel minor key. Just flat the 3, 6, and 7th notes of the Major scale. (To flat a sharp note, lower it a half step by removing the sharp.)


On the Flat side, here's the Bb Major Scale:

Bb C D Eb F G A Bb

Its Parallel minor scale is:

bb c db eb f gb ab bb

As before, the 3, 6, 7th notes of the parallel minor are flat (a half step below), from the Major scale. In this bb minor scale, there are 5 flat and 2 natural notes. Simply remember to play c and f natural, then play all else flat.

Recommended reading: Relative and Parallel minors

Perfect | Augmented | diminished

Perfect

whitney.jpg
whitney houston

Major or minor intervals may change with each scale step (12345678).

However, for both Major and minor scales, a Perfect interval always remains a P4 or P5 (it's perfect like that), and the first and last notes are always the same (P1 or P8).

A simplified explanation: Perfect means the Major and minor scales both have that same interval for their 1, 4, 5, 8 notes.

Key signatures are important for interval identification (knowing steps between a scale's sharp, flat, or natural notes). A Triad is a good starting point, to branch off into different intervals.

We may create more interval types when we further sharp or flat notes in a scale (making the interval notes farther apart, or closer together). The distance in notes is based on half steps between them.

Augmented | diminished

More intervals are Augmented and diminished. To produce these, either sharp a Major interval (Augment it), or flat a minor interval (diminish it).

  • Major 2nd sharped becomes Augmented 2nd
  • minor 3rd flatted becomes diminished 3rd

For both Major and minor scales:

  • Perfect 4th and 5th intervals sharped become Augmented (#4, #5)

  • Perfect 4th and 5th intervals flatted become diminished (b4, b5)

When the interval identification gets confusing, we may listen to the sound of the root compared to the upper note. Intervals are really just half steps, added up. Thinking in terms of steps allows us to make an interval anywhere between two notes. We may flat or sharp a note to change its interval into a Major, minor, Perfect, Augmented, or diminished.

To hear all of the intervals in a scale, play a root note, together with each of its 7 individual scale notes. Then, play the root and next note individually, to hear how far apart in sound they are.

For practice listening to intervals, find a simple song to hear its melody's intervals. For example, the song, "Row Row Row Your Boat" has Perfect unisons (Row, Row, Row), a Major 2nd (Row, Your), and a Major 3rd (Row, Boat). It's also the first three notes of a Major scale (row your boat).

Sharps and flats space out the intervals of notes in a melody. As background chords change, the melody intervals remain the same, but melody notes are sharped or flatted according to the new key of the chord.

Regarding intervals, some musicians focus on certain sound patterns that distinguish their style. This freedom of choice, and the skill to bring it about, is what makes music fun!

Recommended reading: Page 5

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