The "G7 alt" tuning sets your guitar's open strings to the unique sequence of F2 G2 D3 G3 B3 D4, from the thickest (6th) to the thinnest (1st) string. This creates an open and resonant sound, specifically tailored for blues and slide playing.

Verbal Analysis

This tuning is designed to evoke a rich, bluesy landscape, making it "great for lap steel blues" as described by its creator. The open string voicing provides a strong foundation for slide techniques, allowing for fluid glissandos and expressive phrasing without constant re-fretting. While the creator's description mentions a "reentrant" aspect (a non-linear pitch order where a higher-numbered string might be tuned to a higher pitch than a lower-numbered string), the provided tuning notes (F2 G2 D3 G3 B3 D4) actually follow a standard ascending pitch order from the lowest (thickest) string to the highest (thinnest) string. This offers a familiar ergonomic feel for string progression while delivering its distinctive tonal character. It provides a powerful, full sound, particularly suited for open strumming or single-note melodies with a slide.

Technical Analysis

The open string notes are F2, G2, D3, G3, B3, D4. When strummed together, these notes primarily form a G dominant 7th chord (G7) with an F in the bass (G7/F). The notes G, B, and D form a G Major triad, which is then extended by the F note (the minor 7th) on the lowest string, giving it its dominant 7th character. The open G and D notes appear in multiple octaves (G2, G3 and D3, D4), adding to the tuning's resonance and fullness.

The intervallic structure of the open strings is as follows (relative to the lowest string F2):

• String 6 (F2): Root
• String 5 (G2): Major 2nd (from F)
• String 4 (D3): Major 6th (from F)
• String 3 (G3): Octave + Major 2nd (from F)
• String 2 (B3): Octave + Major 4th (from F)
• String 1 (D4): Octave + Major 6th (from F)

Due to the open G7/F voicing, this tuning is highly conducive to playing blues, rock, and slide guitar. Common movable chord shapes that would be effective include:

• Barre Chords: A simple barre across all strings at any fret will produce a dominant 7th chord with a movable root. For instance, a barre at the 3rd fret would yield a Bb7/Ab, and at the 5th fret, a C7/Bb.
• I-IV-V Progressions: Chords based on the root (G7/F), a fourth above (C7/Bb), and a fifth above (D7/C) are naturally accessible with minimal finger movement or slide positions, making classic blues progressions very intuitive.
• Open String Drones: The repeating G and D notes in various octaves allow for rich, sustained drones, which are particularly effective in blues improvisations and adding texture.

How to Tune

To achieve the "G7 alt" tuning from standard E Standard tuning (E-A-D-G-B-e), follow these steps:

• String 6 (Low E string position): Tune up 1 semitone from E to F2. (Note: Moving up 1 semitone is a minor adjustment, generally safe for standard gauge strings.)
• String 5 (A string position): Tune down 2 semitones from A to G2. (Note: Moving down 2 semitones is a minor adjustment, generally safe for standard gauge strings.)
• String 4 (D string position): Keep as is; no change (0 semitones) to D3.
• String 3 (G string position): Keep as is; no change (0 semitones) to G3.
• String 2 (B string position): Keep as is; no change (0 semitones) to B3.
• String 1 (High E string position): Tune down 2 semitones from E to D4. (Note: Moving down 2 semitones is a minor adjustment, generally safe for standard gauge strings.)

As none of the string adjustments exceed the recommended +/- 4 semitones, a change in string gauge is generally not required for this tuning.

String 6 (Low E string position): Tuned to F2 (Low F)

String 5 (A string position): Tuned to G2 (Low G)

String 4 (D string position): Tuned to D3 (Middle D)

String 3 (G string position): Tuned to G3 (Middle G)

String 2 (B string position): Tuned to B3 (Middle B)

String 1 (High E string position): Tuned to D4 (High D)