E13 Tuning

Five of six strings move from C6, and the open strings ring as an E7 with the 13th added. A bar spells seventeen chord types here, more than in any other tuning on this site.

The dominant tuning

E13 is built on a dominant seventh. Its six strings, B D E G# C# E from the low string up, hold E, G#, B and D, an E7 chord, plus C#, the thirteenth. Struck open they ring as E7 with the thirteenth added, or, read from C#, as C#m7 with a flat ninth. Both names fit the same six notes, and the table gives both.

It is the tuning on this site where the bar finds the most: seventeen chord types to C6's eight. It keeps the major and minor triads, the sixth and the minor seventh, and adds the dominant seventh, the thirteenth, the diminished triad and the minor sixth, among others.

The cost is the retune. Five strings move from C6; string 4 moves furthest, three semitones down from G to E, and only string 1 stays on E.

Which E13

More than one six-string row travels under the name. This page publishes B D E G# C# E, the row two independent sources print. Others place the C# or the D differently, but every E13 row the sources print carries the C#, the thirteenth the tuning is named for.

What moves from C6

E13 against C6, string by string, string 1 (the highest) first. Each move is the nearest one that reaches the new note.
String C6 E13 Move
1 E E stays
2 C C# up 1 semitone
3 A G# down 1 semitone
4 G E down 3 semitones
5 E D down 2 semitones
6 C B down 1 semitone

Five of the six strings move. Struck open, the strings ring as E 7add13 or C# m7b9.

What a bar spells

Every chord type a straight bar or a slant spells in E13 or in C6. A type is spelled on all twelve roots or on none, because the bar slides.
Chord type C6 E13
Major yes yes
Minor yes yes
Power (5) yes yes
7 — yes
m7 yes yes
m(maj7) — yes
Dim — yes
maj7sus2 yes yes
maj7sus4 — yes
6sus2 yes yes
6 yes yes
m6 — yes
m6/9 — yes
m(add9) yes yes
13 — yes
7add13 — yes
m7b9 — yes

E13 spells seventeen chord types to C6's eight: nine gained, zero given up.

Where this row comes from