Blues Guitar Institute

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Intervals Lesson: The #1 Reason You’re Lost on the Fretboard

Lesson ID: TB418

There are 138 different note locations on a 22-fret guitar.

With the sheer number of options, it’s no wonder that most of us wander around the fretboard completely lost. I was lost for decades.

But there’s a way to narrow down the dizzying number of options on the fretboard. That’s a way to organize things in your mind and get the sound you’re looking for with confidence.

We can do all this with a basic understanding of one of the most fundamental things about music.

Let’s talk intervals.

What Is an Interval?

The space between two notes.

That’s it.

Everything we do on the fretboard is about the space between notes. Scales and chords are built from a certain pattern of spaces between the notes. If you change the spaces, you change the type of chord or scale.

Change the chords or scales…

…change the music.

Let’s back up a bit before we go any further and answer the question:

What makes a note different from any other?


Playing a note on the guitar causes the string to vibrate. We can measure the vibrations per second or frequency in Hertz (Hz). In standard tuning, the open 5th string on the guitar vibrates at a frequency of 110 Hz, an A note. Different notes have different frequencies. Put your finger on the 5th string, 5th fret and pluck the string. This note – or any other along the string – effectively shortens the string.

The shorter the string, the higher the frequency. The higher the pitch.

Said another way, the difference in frequencies between two notes is an interval.

With that in mind, we can now take a look at our first interval.


Remember that A on the guitar that vibrates at 110 Hz?

Well, the note that vibrates at exactly twice that rate, 220 Hz, is also an A note, of course it’s higher in pitch. The interval between the first note and the one at two times the frequency is an Octave.

Octaves move in the other direction too. The note that vibrates at 55 Hz is also an A note. That one is an octave lower and you’ll have to reach for a bass guitar or piano to play that one. It’s beyond the range of the guitar.

💡 An octave is the distance between two pitches whose vibrates have a 2:1 ratio.

The diagrams below show how to find an octave on a single string and across the strings. Notice that we have a different fingering for the octave shape when we cross the second string. This is because of the tuning interval of the second string. More on that later.

How does the octave sound?

When played together, the octave sounds at rest. It sounds complete. There’s no dissonance at all.

💡 Learning each interval is knowledge. Some say knowledge is power.

Knowledge is only potential power.

It has to be used to be powerful.

Make an effort to learn the sound of the octave and the other intervals we cover later.

Sing the interval. Play the interval on your guitar and try to recognize it in songs. This will help develop your ear which will help you learn and compose faster.

The octave is a large or wide interval. When played melodically – single notes versus together – you hear quite a jump.

Common Examples of an Octave

With each of the intervals, I’ll share a few common examples to help you identify the interval when you hear it. Here are three examples of an octave:

  • Somewhere Over the Rainbow – the notes of “Some” and “where” are an octave apart.
  • Bulls on Parade by Rage Against the Machine – the opening riff moves from the F# on the 4th string down to the F# on the 6th string.
  • Immigrant Song by Led Zeppelin – the opening riff jumps up from the F# on the 6th string to the F# on the 4th string.

Every other interval that we’ll discuss in this lesson is a division of the octave. Think of the octave as the container for the other intervals.

Let’s first look at two intervals that you’ll get a ton of mileage from.

Major Third and Perfect Fifth

There are twelve intervals in an octave but we’ll focus on the ones that make up the major scale – plus a couple bluesy ones.

Nearly everything in western music is referenced from the major scale.

Already know it? Great! This interval discussion will help you get even deeper with the scale.

If you aren’t yet familiar with the major scale, this lesson will help you put it together. You will have everything you need to build the scale by the end of this lesson.

We’re going to shake things up a bit and learn the major scale intervals out of order. There’s a reason for that so hang with me.

Major Third

A major third spans two whole steps or four frets on the guitar.

It is a building block of many chords and scales, and has a distinct sound that can be recognized in many songs.

To find a major third on the guitar, start with a root note and move up two whole steps or four frets. Or, move up one string and down a fret.

Remember, we have to adjust the shape when we cross onto or over the second string.

Examples of Major Thirds

  • Blister In the Sun by the Violent Femmes – the lyrics “When I” from the first line.
  • The Marine Hymn – “From” to “the” in the opening lyric.
  • Ob La Di, Ob La Da by the Beatles – “Ob” to “La”

Perfect Fifth

The Perfect Fifth is seven half-steps or three-and-a-half whole steps between two notes. This interval sounds stable or consonant – at rest.

To find a perfect fifth on the guitar, start with a root note and move up seven frets. Or move across the strings by skipping a string and moving up two frets.

Here is the shape on the second string.

💡 The Perfect label is applied because of the interval’s consonant sound. The perfect intervals are unison, fourth, fifth and octave.

The two twinkles in the song, Twinkle Twinkle Little Star, are a perfect fifth apart. The perfect fifth can also be heard in the opening notes to Metallica’s song, One.

Major Triads and Arpeggios

The Major Third and Perfect Fifth are fundamental intervals found in common chords and scales. They often serve as excellent target notes for licks and solos. Along with the root, these intervals make up the most fundamental chord: the triad.

💡 A triad is a three note chord.

If you play these notes melodically, you have a Major Arpeggio.

💡 An arpeggio is playing the notes of a chord individually.

The chord – or arpeggio – gets it’s name from the note name of the root. This is just one reason why it’s a good idea to learn the note names on the guitar.

We’ve just covered three (Root, Third, Fifth) of the seven intervals that make up the major scale!

Focus on these three intervals first. They are used frequently and will help you know where you are on the fretboard.

Other Intervals of the Major Scale

Next, let’s fill in the gaps with the other intervals found in the major scale.

Major Second

The major second is the distance of two half-steps or one whole step between two notes. It is a common interval found in many scales and chords.

To find a major second on the guitar, start with a root note and move up one fret. Moving across the strings, move up one string and down two frets.

Here’s a diagram to help illustrate how to find the major second interval on the guitar:

And here it is crossing onto the second string:

Play the major second interval on different strings and in different positions on the fretboard to get comfortable with it.

Some common examples of the major second interval in music include the second and third notes of “Happy Birthday.”

Perfect Fourth

A perfect fourth is an interval that spans four half-steps or two whole steps on the guitar. Similar to the perfect fifth, the fourth has a consonant sound.

Play a perfect fourth by moving up the same string by four frets or moving up one string and down one fret.

It has a distinctive sound that can be heard in many songs, including “Amazing Grace” and the opening notes of “Here Comes the Bride.”

The guitar strings – except for the second string – are tuned in fourths.

Major Sixth

The major sixth spans nine half-steps or four-and-a-half whole steps on the guitar.

To find a major sixth on the guitar, start with a root note and move up nine frets on the same string, or up two strings and up one fret.

Here’s a diagram to help illustrate how to find the major sixth interval on the guitar:

Think of the NBC chime for the sound of the major sixth.

Major Seventh

The major seventh interval that spans eleven half-steps or five-and-a-half whole steps on the guitar. It has a distinct sound that can be heard in the 80s song, “Take On Me” by A-ha.

To find a major seventh on the guitar, start with a root note and move up eleven frets on the same string, or up two strings and up one fret.

Here’s a diagram to help illustrate how to find the major seventh interval on the guitar:

Building the Major Scale

Arrange these intervals in numerical order to produce the major scale.

Root, Major Second, Major Third, Perfect Fourth, Perfect Fifth, Major Sixth and Major Seventh.

This pattern of intervals forms the major scale.

So far, we haven’t talked much about notes, but let’s build the C major scale from what we know so far about intervals. The note C, will be our Root.

IntervalHalf Steps Above the RootNote
Major Second2D
Major Third4E
Major Fourth5F
Perfect Fifth7G
Major Sixth9A
Major Seventh11B

Learn the major scale thoroughly. It will pay huge dividends for you on the guitar. Knowing the major scale inside and out will boost your confidence on the fretboard.

But, the intervals in the major scale aren’t the only ones. Remember, there are twelve in the octave. It’s helpful to know them all, but the next two we’ll cover here are extremely useful to blues guitarists.

Two Very Useful Minor Intervals

A minor interval has one half-step less than a major interval.

For each major interval we covered earlier, lower the higher note one fret to find the minor interval.

💡 If you lower a perfect interval by a half step, the interval is diminished (diminished fourth, diminished fifth).

Let’s focus on two very important minor intervals, especially for blues guitarists.

Minor Third

The third interval of a scale or chord defines its overall sound. A scale with a major third will sound happier, brighter whereas a scale with a minor third will sound sad, darker.

The minor third spans three half-steps or one-and-a-half whole steps on the guitar. It has a distinctive, dark sound heard in many songs, including “Iron Man” by Black Sabbath.

Here’s a diagram to help illustrate how to find the minor third interval on the guitar:

Minor Seventh

The minor seventh interval spans ten half-steps or five whole steps on the guitar. It is a key component of many chords and scales and helps give the minor pentatonic scale its bluesy sound.

Here’s a diagram to help illustrate how to find the minor seventh interval on the guitar:

In Summary

Intervals are the backbone of everything that we do on the guitar.

They are the foundation that we build blues, rock, jazz, classical, country, pop music on. They are at the heart of scales and chords. If you’re lost on the fretboard, chances are you need to spend time learning intervals. Learn how they sound and how to find them on the guitar.

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