The Open Em13 tuning for a 7-string guitar is a wonderfully rich and complex sound, perfectly suited for the intricate, melancholic, and often arpeggiated styles found in genres like midwest emo, jazz fusion, and progressive rock. This tuning immediately presents a full, extended minor chord without any fretting, making it an excellent foundation for atmospheric and harmonically sophisticated compositions.

Technical Analysis:

The open strings lay out the following notes from lowest to highest: C2 - E2 - G2 - B2 - F#4 - B3 - D4. When analyzed with E as the root, this tuning forms an E minor (add ♭13, 9) chord. Specifically, the intervals from E are: E (Root), G (minor 3rd), B (perfect 5th), D (minor 7th), F# (major 9th), and C (minor 13th). The presence of the low C string adds a deep, slightly dissonant, yet compelling foundation, giving the Em chord a distinctive, introspective character.

The tuning features a notable jump in pitch between the 4th string (B2) and the 3rd string (F#4), spanning over an octave. This wide interval will create unique voicings and requires players to adapt traditional chord shapes, opening up possibilities for unconventional melodic and harmonic lines. The repetition of B (on string 4 and 2) adds sustain and resonance to the 5th of the chord.

This open chord structure is ideal for shimmering arpeggios, full, resonant strumming, and allows for exploring melodic lines that naturally fall within the Em13 soundscape. Players will find new avenues for creativity by sliding shapes up and down the neck, discovering fresh inversions and extensions that are simply not available in standard tuning.

How to Tune:

Careful attention should be paid to the tuning process for each string. Some strings require significant adjustments, and users should always be mindful of string tension and potential breakage. For movements exceeding 4 semitones up or down, it is generally advised to consider a different gauge string to maintain optimal playability and string integrity.

Open String Notes:

String 7 (lowest): C2
String 6: E2
String 5: G2
String 4: B2
String 3: F#4
String 2: B3
String 1 (highest): D4

How to Tune:

• String 7: Tune up 1 semitones to C2.
• String 6: Keep as is; no change (0 semitones) at E2.
• String 5: Tune down 2 semitones to G2.
• String 4: Tune down 3 semitones to B2.
• String 3: Tune down 1 semitones to F#4.
• String 2: Keep as is; no change (0 semitones) at B3.
• String 1: Tune down 2 semitones to D4.

Important Note on String Tension:
When tuning, especially for changes exceeding 4 semitones (either up or down), please exercise caution. Significant changes in string tension may require a different string gauge to prevent breakage or poor intonation. Always tune gradually.