Why the Guitar is Tuned in Fourths

Why is the guitar tuned in fourths? What benefit does that have? Would it be better to use some other system to tune the guitar?

Why is the "b" string tuned to a third? What effect does that have?

What Do You Want in a Tuning System?

Tuning systems should support the goals of the guitar player using them.

Tuning systems can affect:

• Convenient access to bass notes. Guitar music in D major is often tuned using Drop D to facilitate the D bass note.


• Convenience of key. It is often desirable for open strings to fit the key of the music, so tuning systems are sometimes changed to suit the key of the music.


• String flexibility. Stevie Ray Vaughan famously tuned his guitar down a half step. This reduces string tension, allowing the strings to be bent more.


• Easy to play 6-string chords. For playing 6-string chords, all notes played must fit into the chord. Some guitar tunings make it easier to play such chords by repeating notes, especially by using a barre. Others would make it harder (or impossible) by requiring many complex finger stretches. Standard tuning is a good compromise.


• Ease of memorizing and re-using guitar structures. One disadvantage of standard tuning is that it is inconsistent. The guitar is tuned in fourths, except for the “b” string. This gap creates a major difficulty for learners who must always remember that every guitar pattern they learn will have a different shape if it crosses that string.


• Convenience of learning. It is much easier to learn standard tuning because of the many learning materials that are geared for standard tuning.

Why Fourths?

The reason the standard tuning is in fourths is to give the player easy access to the fullest and smoothest range of notes. Tuning the guitar with a smaller interval, such as tuning in thirds, would result in a system whereby this range is easier to play because fewer stretches are needed, but at the expense of making it less realistic to play simple chords.

What about the “b” string?

Starting on the low “E” string, a series of fourths would be: E–A–D–G–C–F. That’s pretty cool, except now barre chords don’t work as well because there are so many different notes. Instead, the highest string can be tuned to E two octaves above the lowest: E–A–D–G–C–E. This is a better compromise, but now there’s a third between the last two strings. Moving the “C” down to “B” will make the top two strings consistent with the tuning of fourths, which is useful for playing melodies on the top strings, and now we have arrived at standard tuning.

More Information

Standard tuning is only one of many options. For beginners, it is probably best to stick with standard tuning unless your curiosity is really pushing you to explore other tunings. Other tunings can make it easier to bend strings, play in new keys, or incorporate guitar parts taking extensive advantage of repeated open strings.