7 String Standard tuning extends the conventional 6-string guitar's range, typically by adding a lower string for an extended bass register, though it can also be used to expand the treble. As described, the additional string is often accommodated either by widening the fingerboard or by adding a "floating" bass string, similar to historical instruments like the archlute or theorbo, where these unfrettable strings were known as diapasons or bourdons.

Technical Analysis

This tuning is essentially standard E tuning for the top six strings (E-A-D-G-B-E, from low E to high E) with an added seventh string tuned to B, a perfect fourth below the low E string. The open notes are B1-E2-A2-D3-G3-B3-E4.

The intervals between the strings are predominantly perfect fourths, with one major third:

• String 7 (B1) to String 6 (E2): Perfect Fourth (P4)
• String 6 (E2) to String 5 (A2): Perfect Fourth (P4)
• String 5 (A2) to String 4 (D3): Perfect Fourth (P4)
• String 4 (D3) to String 3 (G3): Perfect Fourth (P4)
• String 3 (G3) to String 2 (B3): Major Third (M3)
• String 2 (B3) to String 1 (E4): Perfect Fourth (P4)

This configuration provides an extended bass range, ideal for heavier music genres, progressive rock, or jazz, allowing for deeper melodic lines and richer harmonic voicings.

Open Chords and Accessibility

While the open strings themselves do not form a single simple chord, the tuning is highly versatile:

• All standard 6-string open chords remain directly playable on the top six strings (E, A, D, G, C, Em, Am, Dm, etc.).
• The low B string significantly enhances power chord capabilities. Root notes on B, E, A, D, and G can be easily formed into power chords spanning multiple strings. For example, a B5 power chord can be played on the lowest two strings (B1 and F# fretted on E2).
• Open voicings for chords like E minor (B-E-G-B-E, or even B-E-A-D-G-B-E) or E major (B-E-A-D-G#-B-E with G string fretted) gain a deeper foundation.
• This tuning is excellent for playing in keys related to B, E, and A, providing a powerful bottom end for riffs and complex harmony.

How to Tune

For 7 String Standard tuning, all strings maintain their standard pitch, meaning no adjustments are necessary from a baseline 7-string standard setup. Please note that for general tuning adjustments, significantly altering a string's pitch (more than 4 semitones up or down) may require a different string gauge to prevent breakage or poor intonation.

• String 7 (Low B): Keep as is; no change (0 semitones).
• String 6 (Low E): Keep as is; no change (0 semitones).
• String 5 (A): Keep as is; no change (0 semitones).
• String 4 (D): Keep as is; no change (0 semitones).
• String 3 (G): Keep as is; no change (0 semitones).
• String 2 (B): Keep as is; no change (0 semitones).
• String 1 (High E): Keep as is; no change (0 semitones).

String 7: B1
String 6: E2
String 5: A2
String 4: D3
String 3: G3
String 2: B3
String 1: E4