Tuning Overview: G7 Lap Steel Blues

This is a distinctive and expressive tuning, named 'G7 Reentrant 7 string,' and is deeply rooted in lap steel and Dobro playing traditions, particularly within the blues genre. The original description from Allan highlights its practical application as 'Allans 7 string lap steel or Dobro tuning fGBDGBD' and characterizes it as 'A nice blues tuning.' While the tuning's name and description suggest a reentrant quality—with the description specifically stating, 'The f on string 7 is tuned higher than the G on string 6'—our analysis of the provided tuning notes shows a generally ascending pitch from the lowest string (String 7) to the highest (String 1), meaning String 7 (F2) is actually lower in pitch than String 6 (G2).

Technical Analysis: Open G7 Voicing

The open strings are tuned as follows, from the lowest (thickest, String 7) to the highest (thinnest, String 1): F2, G2, B2, D3, G3, B3, D4. This specific arrangement of notes effectively spells out a G7 chord (G-B-D-F). The F2 on the lowest string acts as the minor seventh of G, giving the tuning a rich G7/F voicing. The deliberate distribution and doubling of G, B, and D notes across the strings create a full, resonant, and harmonically complete open chord, which is perfectly suited for slide guitar.

Chordal Possibilities:

• Open G7 Chord: The most immediate and powerful feature of this tuning is the open G7 chord that rings out when all strings are strummed without fretting. This provides an instant blues foundation and is exceptionally well-suited for expressive slide playing.
• Bar Chords: By employing a slide or simply barring a finger across a single fret, you can effortlessly transpose the open G7 chord to any other dominant 7th chord. For instance, a bar at the 1st fret yields a G#7, at the 2nd fret an A7, and so forth, facilitating smooth chromatic or diatonic chord progressions.
• Triads & Extensions: The repetition of G, B, and D notes means that various major and minor triads, as well as extended chord voicings, are often readily accessible by fretting just one or two strings. This allows for nuanced melodic fills and more complex harmonic movements within the overarching G7 framework.

How to Tune:

To achieve this G7 Lap Steel Blues tuning, you will typically adjust your 7-string guitar from a standard B E A D G B E tuning. It is crucial to pay close attention to the semitone movements. For changes exceeding 4 semitones (either up or down), using a different string gauge is highly recommended for optimal string tension, playability, and to prevent string breakage.

• String 7 (Lowest, B2 standard): Tune up 6 semitones to F2. Caution: This is a significant increase in tension (+6 semitones); a heavier gauge string is strongly advised.
• String 6 (E2 standard): Tune up 3 semitones to G2. Caution: This is a notable increase in tension; proceed carefully.
• String 5 (A2 standard): Tune up 2 semitones to B2.
• String 4 (D3 standard): Keep as is; no change (0 semitones).
• String 3 (G3 standard): Keep as is; no change (0 semitones).
• String 2 (B3 standard): Keep as is; no change (0 semitones).
• String 1 (Highest, E4 standard): Tune down 2 semitones to D4.

Open String Notes:

• String 7 (Lowest): F2
• String 6: G2
• String 5: B2
• String 4: D3
• String 3: G3
• String 2: B3
• String 1 (Highest): D4