How to Play intervals 1 through 7 on the Guitar
On the guitar, the distance from the 1st to the 2nd scale degrees in the major scale is called a second interval, from the 1st to the 3rd is called a third, from the 1st to the 4th is called a fourth, and so on. Here’s what makes up each interval:
2nd: A whole step above the 1st scale degree.
3rd: Two whole steps or over a string and back one fret.
5th: Three and a half steps or over a string and up two frets.
6th: Four and a half steps or over two strings and back one fret. (The same note is also over one string and up two whole steps.)
7th: Five and a half steps or over two strings and up one fret. (A 7th is one half step shy of an octave.)
Whenever you move from string 3 to 2 to play an interval, you need to move up an extra fret because the 2nd string is tuned a half step lower than the others. For example, a 3rd is normally over a string and back one fret, but when moving from string 3 to 2, a 3rd is over a string and in the very same fret.
Normally a 4th is over one string, but it’s up one fret from string 3 to 2.
Moving from the 6th string to the 1st, everything changes at the 2nd string, and an extra fret is needed. Because the 1st string is tuned to the 2nd string in the same manner that strings 6 to 3 are tuned, intervals between them are normal.
Guitarists often play what are known as harmonic intervals, which are really just intervals you play together to create harmony. Thirds are a common type of harmonic interval.
To play thirds, play the 1st and 3rd scale degrees simultaneously and then ascend or descend the scale in groups of two with the notes always 3 scale degrees apart. You can do this in five different positions by following the tab in the image below. You can see this at Playing Thirds.
You can play in 3rds in other keys by starting at a different fret and using the same interval shapes. For example, start on A at the 5th fret of the 6th string to play 3rds in the A major scale.
Many songs feature guitar parts played in 3rds. One of the best examples is the opening to Brown Eyed Girl by Van Morrison. The guitar plays the G major scale in 3rds over the G chord and the C major scale in 3rds over the C chord.
6ths (or inverted 3rds)
Sometimes guitarists invert 3rds by moving the 1st degree up an octave. What was 1-3 becomes 3-1. The interval is inverted, get it? For example, G-B would become B-G. Here are two examples of inverting the 3rd G-B.
With intervals, you always count from the note in the lowest position to the note in the highest position. Thus, inverted 3rds are more commonly called 6ths. G to B is 3 scale degrees (G-A-B, one-two-three), so the interval is called a 3rd. B to G, on the other hand, is 6 scale degrees (B-C-D-E-Fs-G, one-two-three-four-five-six), so it’s called a 6th.
You can play through the whole scale in 6ths in two different positions by following the tab below. Because you only want to sound the notes in the tab and not the other strings, and because these interval shapes are two strings apart, you need to either fingerpick or apply some left-hand muting technique (like you do with octave shapes).
Harmony-wise, when you play in 6ths, you hear 3rds and roots, but technically, the distance between each pair of notes from low to high is identified as a 6th. For example, Brown Eyed Girl by Van Morrison features 6ths throughout the song.
By far, the most popular type of harmonic interval among guitar players is the 5th. After all, a root and a 5th make up the so-called power chord that appears in almost every distorted rock song ever recorded. (Technically, a power chord isn’t a chord because chords have to include three or more notes.)
Think about the opening to songs like Rock You Like a Hurricane by The Scorpions, Hit Me with Your Best Shot by Pat Benatar, and anything by Black Sabbath, Nirvana, Kiss, or the Ramones — just to name a few.
A 5th is written as G5, A5, and so on in a chord chart. Here is a G scale in 5ths in two different positions.
4ths (or inverted 5ths)
Sometimes guitarists invert 5ths by moving the lower note up an octave while keeping the upper note the same. For instance, G-D would become D-G.
Inverted 5ths are more commonly called 4ths for the same reason that inverted 3rds are called 6ths. G to D is a 5th (G-A-B-C-D), while D to G is a 4th (D-E-Fs-G).
You can play the G major scale in 4ths by following this tab:
In harmony, when you play in 4ths you hear the upper note of the interval as the root and the lower one as the 5th, but technically, the distance between each pair of notes from low to high is a 4th.
By far the most famous example of using 4ths is in the song Smoke on the Water by Deep Purple. The opening guitar riff uses 4ths in G minor. Other songs include Money For Nothing by Dire Straits and Wish You Were Here by Pink Floyd.