# Music Intervals: What Is An Octave & What Are Intervals?

There are 13 music intervals and an octave is an interval that contains all the simple intervals within it. An octave spans the distance of all 12 chromatic scale notes and the 13th note is the octave.

Music intervals are vital to understanding how to build scales and chords. It is the octave that is divided into 12 equal parts (semitones) that create the notes of the chromatic scale.

Every consecutive semitone away from a starting point is a different music interval, and they are all extremely easy to understand.

## What is an octave?

If you what to truly understand what an octave is, then you need to know a number of music terms. The most important terms to know are pitch, chromatic scale, semitone, and music intervals.

Pitch is the specific frequency and sound of any single note on any instrument measured in Hertz (Hz)

The chromatic scale is the scale that contains the 12 pitches\notes that are used to make music.

A semitone is a distance between adjacent notes in the chromatic scale (also called a half step).

Music intervals are the 12 distances from a starting pitch until you reach the 13th note (the octave).

#### A few different ways to define an octave

1. An octave is the music interval that contains within it all the other simple music intervals.
2. Octaves span the distance of 12 semitones.
3. An octave is divided into 12 equal parts (half steps) and those divisions make the 12 notes of the chromatic scale.
4. An octave is a distance from a note at a specific frequency to the next note that is double that frequency.

The chromatic scale is created by dividing the octave into 12 equal parts called semitones. Intervals, the octave, and the chromatic scale are closely related.

It’s a little confusing. You need the term “octave” to explain the chromatic scale, and you need the chromatic scale to understand what intervals are. Let’s look at a practical example.

If you have heard orchestras tuning up in person or on TV, then you are hearing the musicians playing concert A at 440 Hz.

If a second note is played at double the frequency (880 Hz), then that would be A one octave higher. A note at triple the frequency (1760 Hz) would be two octaves higher than concert A.

The “distance” of an octave spans a total of 12 notes or semitones, the entire chromatic scale. It is actually 13 notes when you count the first and last notes.

That’s what an octave is. It is the music interval that starts on a chromatic scale note and ends on the same letter note at double the frequency.

Alright, let’s skip the physics lessons on pitch frequency and get into one of my favorite subjects: intervals.

## What are intervals? Music intervals explained

Music intervals are the distances between a starting note and any higher chromatic note up to and including the octave. There are 13 music intervals from a starting pitch up to the octave.

A music interval is the distance between 2 notes and is described by a number and a quality. But first, do you understand the word “distance” in this context?

An English ruler is divided into 12 parts called inches. Think of each inch as a semitone of the chromatic scale. The distance between semitones is the same as between inches except music intervals involve frequencies and pitch ratios.

Also note, I’m skipping some intervals that I feel are ridiculous like diminished 4ths and augmented octaves.

### Music Interval numbers

An easy way to understand interval numbers is to look at an example. Keep in mind there are only 7 letter names used in music, the first 7 letters of the alphabet: A thru G. Here are the notes of the A natural minor scale:

The 1st note of the scale is A is because it is the “first”. Following that logic, B is the 2nd, C is the 3rd all the way up to G the 7th. The 1st thru the 7th are the interval numbers.

And you do not skip letters even if a scale lacks some of the 7 notes. For example, here is the A minor pentatonic scale:

The distance from A to C is still a 3rd even though there is no B in the scale. That fact is important. The numbers involve ALL the letters whether they are present in a scale or not.

### Music Interval qualities

The possible interval #’s are 2nds, 3rds, 4ths, 5ths, 6ths, and 7ths. Those intervals can have a quality of perfect, major, minor, diminished or augmented. Unisons and octaves are unique intervals and are covered below.

Let’s look at the interval qualities to better understand intervals.

#### Perfect intervals

The perfect interval numbers are 4ths and 5ths. Unisons and octaves are also perfect intervals. Most of this is informational only, so don’t get too worried if you do not understand everything.

A unison is an interval of a note and a note at the same frequency (the same note). If you play the A note on the low E string at the 5th fret and the open A string, then that is an example of a unison.

Unisons are the first of the perfect intervals. Perfect unisons have a frequency ratio of 1:1. An example is A 440 and A 440. The symbol is either PP for Perfect Prime or P1. Some people will use PU for Perfect Unison but I say PU stinks.

Octaves are perfect intervals and have a pitch frequency ratio of 2:1. They are separated by 12 semitones. Think the open A string and the A at the 12th fret on the same string. An example is A 440 Hz and A 880 Hz. The abbreviation is P8 or 8ve.

A perfect fourth (P4) is a note that is 5 semitones (5 frets) above the starting pitch and has an ideal pitch frequency ratio of 4:3 (ex. A to D).

The last perfect interval is the perfect fifth (P5) and is a note that is 7 semitones (7 frets) above the starting pitch and has an ideal frequency ratio of 3:2. (ex. A to E).

#### Major intervals

Let’s change to the notes of the C major scale:

The major scale is called the major scale because the interval qualities of the 2nd, 3rd, 6th & 7th notes are major. The distances from C to D, E, A & B are defined as “major” intervals.

C to D is a major second (notated M2) and spans the distance of 2 semitones, which is also called a whole step. So a major second is the distance of 2 semitones.

C to E is a major 3rd (M3) and E is 4 semitones above C. A major 3rd is the distance of 4 semitones.

C to A is a major 6th (M6) and A is 9 semitones above C. A major sixth is the distance of 9 semitones.

C to B is a major 7th (M7) and B is 11 semitones above C. A major seventh is the distance of 11 semitones.

#### Minor intervals

Minor intervals are major intervals decreased by one semitone. We need to reduce the notes of the major scale by a semitone to describe the minor intervals.

C to D♭ is a minor 2nd (m2) and D♭ is 1 semitone above C. A minor 2nd is the distance of 1 semitone.

C to E♭ is a minor 3rd (m3) and E♭ is 3 semitones above C. A minor 3rd is the distance of 3 semitones.

C to A♭ is a minor 6th (m6) and A♭ is 8 semitones above C. A minor sixth is the distance of 8 semitones.

C to B♭ is a minor 7th (m7) and B♭ is 10 semitones from C. A minor seventh is the distance of 10 semitones.

#### Diminished intervals

I’m going to deviate from the classical definition of diminished intervals and say that there are only 2 interval numbers that can be diminished: the 5th and 7th.

C to G♭ is a diminished 5th (d5) and G♭ is 6 semitones above C. A diminished 5th is the distance of 6 semitones. A diminished 5th is also known as the tritone.

C to B♭♭ is a diminished 7th (d7) and B♭♭ is 9 semitones above C. A diminished 7th is the distance of 9 semitones. You only see a d7 in the diminished 7th chord in songs.

#### Augmented intervals

Here is another interval quality where I don’t agree with standard conventions. From a chord naming point of view, I believe only 3 interval numbers can be augmented: the 2nd, 4th & 5th.

C to D# is an augmented 2nd (A2) and D# is 3 semitones above C. An augmented 2nd is the distance of 3 semitones. It’s the same distance as a minor 3rd.

C to F# is an augmented 4th (A4) and F# is 6 semitones above C. An augmented 4th is the distance of 6 semitones. This interval is also known as the tritone.

C to G# is an augmented 5th (A5) and G# is 8 semitones above C. An augmented 5th is the distance of 8 semitones. It’s the same distance as a minor 6th.

#### Music Intervals of the major scale

The music intervals of the major scale are all major or perfect, hence the name “major” scale. But most of the intervals can be understood if you look at the notes of C major but starting and ending on F (F Lydian mode) and starting and ending on B (B Locrian mode).

The intervals that B Locrian lacks, F Lydian has and vice versa. Check this out (I’ve never seen this anywhere else):

Of course, both modes have unisons and octaves. And I hoped you noticed that B & F are the 2 notes that make up the tritone in the C major scale.

The only intervals that are not included are the enharmonic intervals augmented 2nd (#9 = m3) and augmented 5th (#5 = m6). I cover the scales where they come from in different articles.

Now let’s look at some other characteristics of music intervals.

#### Enharmonic music intervals

There are 3 intervals listed above that are enharmonic intervals. Hopefully, you are familiar with enharmonic equivalents. The reason why you would use one over the other has to do with standard notation.

First is the augmented 2nd (C to D#) and the minor 3rd (C to E♭). D# and E♭ are the same note but are a different interval number from C.

Second is the augmented 4th (C to F#) and the diminished 5th (C to G♭). F# and Gb are the same note but are a different interval number from C.

And the third is the augmented 5th (G#) and the minor 6th (A♭). These are also the same note.

Some examples of enharmonic intervals in chords would be (R = root note):

7#9 vs m7
C7#9 = C-E-G-B♭-D# = R-M3-P5-m7-A2 =1-3-5-♭7-#9
Cm7 = C-E♭-G-B♭ = R-m3-P5-m7 = 1-♭3-5-♭7)

7#11 vs 7♭5
C7#11 = C-E-G-B♭-F# = R-M3-P5-m7-A4 = 1-3-5-♭7-#11
C7♭5 = C-E-G♭-B♭ = R-M3-d5-m7 = 1-3-♭5-♭7

7#5 vs 7♭13
C7#5 C-E-G#-Bb = R-M3-A5-m7 = 1-3-#5-♭7
C7♭13 = C-E-G-B♭-A♭ = R-M3-P5-m7-m6 = 1-3-#5-♭7-♭13

#### Music Interval inversions

I’m not sure if knowing inversions will make a difference in your guitar playing, but they are interesting. Let’s look at some examples.

C to D is a major 2nd, but D to C is a minor 7th. You invert an interval by raising the lower note by an octave. The general rule is 2nds invert to 7ths, 3rds invert to 6ths, 4ths invert to 5ths, 5ths to 4ths, 6ths to 3rds, and 7ths to 2nds. Here are all the interval inversions:

1. Minor 2nds invert to major 7th’s. Example: B to C becomes C to B.

2. Major 2nds invert to minor 7ths. Example: C to D becomes D to C.

3. Minor 3rds invert to major 6th’s. Example: A to C becomes C to A.

4. Major 3rds invert to minor 6th’s. Example: C to E becomes E to C.

5. Perfect 4ths invert to perfect 5ths. Example: C to F becomes F to C.

6. Tritones (augmented 4ths OR diminished 5ths) invert to tritones. Example: B to F becomes F to B.

7. Perfect 5ths invert to perfect 4ths. Example: C to G becomes G to C.

8. Minor 6ths invert to major 3rds. Example: A to F becomes F to A.

9. Major 6ths invert to minor 3rds. Example: C to A becomes A to C.

10. Minor 7ths invert to major 2nds. Example: E to D becomes D to E.

11. Major 7ths invert to minor 2nds. Example: F to E becomes E to F.

12 & 13. Unisons invert to octaves and octaves invert to unisons.

If you find interval inversions confusing, then forget about them for now.

#### Compound Music intervals

Compound intervals span more than one octave and are useful in naming chords. Let’s look at C major again:

C – D – E – F – G – A – B – C’ – D’ – E’ – F’ – G’ – A’

The notes with an apostrophe (‘) are numbered as the 8th, 9th, 10th, 11th, 12th and 13th, where the 8th and 12th are unimportant for this article. You sometimes will encounter the 10th with double-stops or fingerpicking (e.g., Blackbird by the Beatles).

I feel the important compound intervals are the 9th, 11th and 13th. Have you ever heard of an add9, a m11 or 13th chord? If you have then now you know the note that is added to the chord that results in the name.

For example, a C add9 chord has the notes C-E-G-D, where D is the 9th and is added to the C major triad. If you add a minor 7th or a major 7th, then the chord becomes a C9 and Cmaj9 respectively. See if this makes sense:

9 = 7 +2, 11 = 7+4, 13 = 7+6. Do you understand?

If things are starting to make sense, then you are getting real close to understanding how all scales and chords are built.

#### Consonant vs, dissonant intervals

Consonant means “sounds good” and dissonant means “not so good”. The consonant intervals are the unison, minor and major 3rd, the perfect firth, the major 6th, and the octave (P1, m3, M3, P5, M6, P8).

Don’t discount all the other intervals just because they are considered dissonant. It’s the dissonant (nasty) notes and intervals that hurt so good, especially when you resolve to a feel-good (consonant) interval.

Consonant and dissonant intervals are sounds you need to hear.

### Music intervals chart

This is a website about guitar chords so it’s time for the “real” names of the intervals. The fretboard intervals chart above is based around A.

The chart alternates using R for Root, T for tonic or just the note A. Also note that I also couldn’t fit #11 and b13 into the circles so I made them #4 and b6. I also randomly switched between the enharmonic intervals.

Here are the intervals as I see them, especially for naming chords:

Minor 2nd = ♭9

Major 2nd = 9, or the ninth, or “the 9”, or the 2 for sus2 chords.

Augmented 2nd = #9 as in 7#9

Minor 3rd = the flat 3 \ ♭3

Major 3rd = the third \ 3rd or just 3

Perfect 4th = the 4, the four, the fourth, the 11

Augmented 4th = #11

Diminished 5th = the ♭5! Think the blues, baby.

Perfect 5th = the five, the 5, the V, the 5th, the dominant V, the dominant 5th

Augmented 5th = #5, aug5, +

Minor 6th – ♭13

Major 6th = 6, the 6th, the 13, 13, 13th

Minor 7th = the ♭7

Major 7th = major 7th, maj7, M7

#### Chord based music intervals

As I see it, the progression of notes from the 1st to the compound interval of the 13th goes as follows:

1 – ♭9 – 9 – #9 \ ♭3 – 3 – 4 \ 11 – #11 \ ♭5 – 5 – #5 \ ♭13 – 6 \ 13 – ♭7 – maj7

Boom! Done! What else do you need to know? Answer: not much.

These are the names of the intervals you will see for any chord you encounter. The one exception would be the major 2nd used in sus2 chords.

You can now build every and any scale and chord that you want to. And you can name any scale degree or chord tone that you encounter.

So for all the music theory haters: What’s the problem, man? It’s so unbelievably simple. And yes, I know F double sharp and B# are actually G and C respectively. I cover that stuff in another article.

### Interval Ear Training

Being able to identify intervals by ear helps in so many ways. You can transcribe cover songs easier, improvise better, and make your own music using your ear. And after all, it’s your ear and creativity that matters – not your instrument.

Ear training tip #1: Tuning by ear.

Start by tuning the low E with an electronic tuner and then tune the other strings at the 5th fret (4th for the B string). Once you can do that, then you have done ear training for the simplest of all intervals: the unison.

Ear training tip #2: Identifying octaves

Play any open string and then fret and play the note on that string at the 12th fret. That’s an octave. Try to contrast octaves with unisons. Also, you could tune with harmonics to help identify octaves, but that is for extra credit.

#### How to identify other music intervals

Ear training tip #3: Perfect 4ths and 5ths.

Next, you want to identify the other perfect intervals: perfect fourths and fifths. Blues progressions are great for that, especially 12-bar with this format:

| I – IV – I – I | IV – IV – I – I| V – IV – I – V | or

| 1 – 4 – 1 – 1 | 4 – 4 – 1 – 1 | 5 – 4 – 1 – 5 |

You can play a 12-bar blues tune with just the root notes of the chords. That is for ear training only. If you play that for other people, they will think you suck at guitar.

Since we mentioned the blues, the next obvious note is the ♭5. That note is unmistakable if you ask me. Keep in mind that the b5 is an enharmonic interval of the #11.

So you now can identify the unison, the P4, ♭5, P5 and octave – that’s 5 of the 13 intervals.

The next intervals are up to you. Minor and major thirds and sixths are a good choice, but so are ♭7’s and major 7’s. And don’t forget ♭9.s and major 9’s.

Ear training tip #4: The next 2 easiest intervals to identify are the ♭9 and M7.

The ♭9 sounds horrible (IMO) and you can really hear how the major 7th wants to resolve to the 1st.

You may need a guitar Buddy who is at the same level as you are, otherwise, you need to try singing each interval after plucking a note.

Or you could try recording all the intervals as separate files and putting them on random play. Then try to identify them by ear. You will have to change them often as you will begin to recognize the pitches.

#### How to use intervals (resolving tendency)

Here are the resolving tendencies of all the intervals. I played each interval note one at a time to find the note or chord that sounded like resolutions, or the final chord of a song.

UnisonOctave (P1 \ P8 or 8ve): resolves like a V7 chord. For example, playing G-G’ resolves smoothly to C major, and a slightly to the relative minor, A minor. The practical application is to play an octave of the perfect 5th of the next chord. So if the next chord is Cmaj7, plag an octave of G.

Minor 2nd (♭9) & major 7th (M7): The example notes here would be C-B-C or just C-B or B-C. The B acts as a leading tone and resolves nicely to C major, not so much to A minor. And this interval is VERY dissonant.

Major 2nd (9) & minor 7th (♭7): Playing G-F or F-G resolves nicely to C major. Think of the notes as the Root and ♭7 of the V7 chord.

Minor 3rd (♭3) & major 6th (M6): Think of the ii chord in C major: Dmin. The D-F or F-D interval wants to resolve to C major. You could look at that interval as the P5 and ♭7 of the V7 chord. Just play the 1st two notes in any minor pentatonic scale and resolve down a whole step. And it sounds pretty good going to A minor.

Major 3rd (M3) & minor 6th (♭13): This acts as the root and major third of the V chord, or G-B-G resolving to C major.

Perfect 4th (p4) & perfect 5th (P5): C-G-C resolves to C major.

Augmented 4th (#11) and \ or diminished 5th (♭5), the tritone: The easiest interval to figure out is the tritone. For example, the major 3rd and ♭7 in a G7 chord (B & F) is the tritone in C major and wants to resolve to C major.

#### Music intervals: songs as examples

Also, don’t bother searching for songs where an interval is easily identifiable unless you are also going to download all the song examples. Just use your guitar and your ear, though if you are interested in hearing famous song examples, here are two worthwhile links:

And I’m not an expert on ear training, so for more information check out Ear Training by Justin Sandercoe. He’s a great guitar player so take a look at his YouTube channel as well.

## Guitar interval shapes

Here are the music intervals I use, as well as other players. FYI, rarely does anyone play 2nds or 7ths.

Sixths are huge in country and bluegrass and they sound fantastic. Thirds are really sweet and a song example using them is the main riff in Brown-Eyed Girl by Van Morrison.

Tenths are just 3rds an octave higher and they sound better than thirds. Search for tablature on Blackbird and you’ll see them in action.

And fifths, or “power chords”, are common in rock. But I’ve never seen anyone mention “Power 4ths” (that’s my name for them). Fourths have an interesting sound.

Keep in mind that 4ths invert to 5ths and vice versa, so the power 4ths and 5ths are mixed. For example, an A power chord is A-E-A, where A to E is a perfect 5th, but E to A is a perfect 4th.

I also included the nasty tritone interval – a masty sound that feels good. These are great for Blues or to CRASH back into the I chord, or tonic of the song.

The numbers in the circles are my suggested fingers to use. White circles are the root note (the 1st) and black circles are the other note in the interval. Also, these are your standard vertical chord blocks where the far left vertical line is the low E and the far right is the high E string.

## Summary

You must learn and totally understand all of the music intervals. And once you understand them, then understanding how to build scales and chords is easy.

When you can do that, then you won’t have to ask someone “What is the name of this chord”?