Intervals & Fretboard Landmarks

The distance between two notes has a name. That name is an interval. Understanding intervals is what separates guitarists who memorize shapes from guitarists who understand the instrument. The fretboard isn't random - it's a grid built on consistent interval patterns.

Half Steps and Whole Steps

On the guitar, one fret is one half step. Two frets is one whole step. Every other unit of pitch measurement in Western music is built from these.

Standard guitar tuning is EADGBe. Most adjacent string pairs are a perfect 4th apart (E to A, A to D, D to G, B to e). The exception: G to B is a major 3rd. That exception is why chord shapes shift slightly between string groups - something every guitarist eventually needs to account for.

Naming Intervals

Intervals are counted from a root note. From C:

C to C - Unison (0 half steps)
C to D - Major 2nd (2 half steps)
C to E - Major 3rd (4 half steps)
C to F - Perfect 4th (5 half steps)
C to G - Perfect 5th (7 half steps)
C to A - Major 6th (9 half steps)
C to B - Major 7th (11 half steps)
C to C - Octave (12 half steps)

Minor intervals are one half step smaller than their major counterparts: a minor 3rd has 3 half steps, a major 3rd has 4. That one-fret difference is the gap between major and minor chords.

Intervals Across the Guitar Neck

Because most adjacent strings are tuned a 4th apart, a note on one string has its perfect 5th two strings up and two frets down (on most string pairs). Its octave sits two strings up, two frets up.

The G-B string break shifts these patterns. When crossing between G and B, subtract one fret from wherever you expected to land. This is not a flaw to work around - it's the reason open chord shapes work the way they do.

Using Intervals in Your Playing

When you move a power chord up and down the neck, you're moving a root-to-5th interval shape. When you bend a string, you're targeting a specific interval - typically a whole step (two frets) in rock and blues. Knowing what you're doing gives you control instead of guesswork.

Practice Exercise

Pick any fret on the low E string. Find the same note one octave higher. Then find it again on a different string pair. A note's octave appears in multiple places on the guitar neck - mapping them trains your interval recognition and your knowledge of the fretboard simultaneously. Do this for five different starting notes over a week.

Questions and Answers

What is an interval in music?: An interval is the distance between two pitches, measured in half steps. On the guitar, one fret equals one half step. Common intervals include the major 3rd (4 half steps), perfect 4th (5 half steps), perfect 5th (7 half steps), and octave (12 half steps).
Why is the G to B string interval different from the other guitar string pairs?: Standard guitar tuning places adjacent string pairs a perfect 4th apart, except for the G and B strings, which are a major 3rd (4 half steps) apart. This exception affects how scale and chord shapes shift between these strings. When moving a pattern across the G-B boundary, most shapes shift one fret lower.

Next up: Keys and Key Signatures - how intervals group into scales and keys, and why certain chords always appear together.