What Chord Is Standard Tuning?

If you strum all six open strings on a guitar—in standard tuning—what chord are you playing?

Every guitar player with a slight interest in music theory asks this question at some point. It may not be useful information, but it’s interesting to think about.

There are many ways to interpret the same combination of notes (E, A, D, G, B, and E). Since we’re not thinking about the chord in a musical context, the answer relies on a bunch of assumptions. The easy answer is E minor 7 ^{add 11.} The REAL answer requires context.

Deciding what to call a chord is a matter of interpretation. Naming the chord formed by the open strings of a guitar is really a guessing game.

Because it’s fun and interesting to think about, let’s dive in.

Building the Open-String Chord

Before we can decide what chord is sounding when we strum the open strings of a guitar, we need to understand how to analyze the chord.

Since we have no musical context, we’ll make two assumptions about our mystery chord:

1. The low-E string is our root note (i.e. the chord isn’t an inversion).
2. We’re in the key of E minor.

First, we’ll make a chart of the six open strings and their scale degrees:

String	E	A	D	G	B	E
Scale Degree	1	4	7	3	5	1

While the string names look familiar, the scale degrees aren’t arranged in a useful way. This is why many guitarists can’t identify the chord name.

If we put those numbers in order—and discard the extra E—we get something like this:

String	E	G	A	B	D
Scale Degree	1	3	4	5	7

As you may know, 1-3-5-7 in a minor key builds a minor 7 chord. We don’t know which key we’re in because the notes of the open strings don’t have a ninth degree (that’s F♯ in the key of E minor, for instance).

But we had five unique notes. That minor 7 chord only uses four notes. What about the 4th degree? How does that fit into things?

Chords are typically built with intervals of thirds. That means the second, fourth, and sixth scale degrees get moved up an octave. This is where we get chord extensions like 9, 11, and 13.

Since the fourth scale degree becomes an 11, the proper way to configure the open-string notes looks like this:

String	E	G	B	D	A
Scale Degree	1	3	5	7	11

Since there is no 9, we can’t technically call this chord an E minor 11. So we’re left with an E minor 7 ^{add 11}.

Other Possible Chord Names: Inversions

Since our chord has five notes and no musical context, we can also consider possible chord inversions. An inversion is a chord that doesn’t have the root note in the bass (lowest note).

The order of the notes doesn’t change unless we change the tuning of the guitar. So the bass note for all of these inversions will be E, which will be indicated by a forward slash and the letter E after each chord name.

A Root

String	A	E	G	B	D
Scale Degree	1	5	7	9	11

This inversion is missing a third degree. That means we don’t know if it’s major or minor, but we have all the other notes for an A11 or an A minor 11. Without the third, we can call it A5 ^{add7 add7 add11}/E.

It’s not a pretty name. Oh well.

D Root

String	D	A	E	G	B
Scale Degree	1	5	9	11	13

Again, we don’t have a third. This time we don’t even have a seven. The best we can do here is D5 ^{add9 add11 add13}/E.

G Root

String	G	B	D	A	E
Scale Degree	1	3	5	9	13

This chord inversion looks promising. We at least have a 1-3-5. In this case, it’s a G major triad. The full chord name would be G ^{add9 add13}/E.

B Root

String	B	D	A	E	G
Scale Degree	1	3	7	11	13

Since we can determine whether the chord is major or minor with just a root and third, the fifth degree isn’t always needed for naming. B, D, and A imply a Bm7 chord. If we happen to be in the key of C major/A minor, the fifth degree (F natural) would give us a Bm7♭5.

The information available leaves us guessing. A possible interpretation is Bm7 ^{add11 add13}/E.

What Scale Is Standard Tuning?

While the open-string notes of a guitar don’t form one definitive chord, they do contain all the notes of a scale you’re probably familiar with: the E minor pentatonic scale.

That’s right. As we discussed earlier, the chord formed by the open strings doesn’t have a 9 or a 13 (the second and sixth scale degrees). Let’s write out the notes of an E minor scale:

Note	E	F#	G	A	B	C	D
Scale Degree	1	2	3	4	5	6	7

First off, if we remove two notes from a seven-note scale, we’re left with five notes (“penta” means five). A minor scale without the 2nd and 6th degrees is a minor pentatonic scale.

That means not only the open strings, but any time you barre a fret, you have the notes of a minor pentatonic scale under your finger. This information may not be useful, but it’s kind of cool.

Musical Context

As we’ve already discussed, the open strings of a guitar don’t indicate which key we’re in. With certain notes missing, we could be in the key of A minor (no sharps or flats), E minor (one sharp), or B minor (two sharps).

That’s where musical context comes into play.

The open strings are missing the notes F and C, which are the exact notes that would indicate the key center. The key center is ambiguous unless someone plays F and C, F♯ and C, or F♯ and C♯.

These missing notes could be played in a chord or melody before, during, or after the open-string chord.

Adding the missing notes would give us all seven notes of a diatonic scale. Played as a chord, we could interpret this as any one of several possible 13th chords.

Conclusion

While the open strings of a guitar do form a chord, it’s not a very pleasant one. It’s also not very useful. Perhaps it’s even less useful to know that it’s an E minor 7 ^{add 11}.

The important lesson is that chord names—other than simple triads—are flexible. Often, we can only guess the names if we don’t know what chord came before, which chord is next, or how the chord is being used.

As we determined above, the open strings of a guitar can have any of the following names depending on which note we decide is the root:

Root	Chord Name
E	Em7 add 11
A	A5 add7 add7 add11
D	D5 add9 add11 add13
G	G add9 add13
B	Bm7 add11 add13

These names don’t consider chords with altered notes or chromatic notes that don’t belong in the key. We’re only looking at the notes we have available.

Now it’s up to you to decide if this information is useful for making music or just another bit of trivia to shove into your brain.