Every Interval, One Shape

Standard tuning forces you to learn different finger patterns for the same interval depending on which strings you cross, because of the major-3rd gap between G and B. Fourths tuning eliminates that problem: every interval has exactly one geometric shape, and it works everywhere on the neck.

Why One Shape?

Every adjacent string pair is separated by 5 semitones (a perfect 4th). That uniformity means the fret relationship between any two strings is always the same. A shape that produces a major 3rd on strings E-A also produces a major 3rd on strings D-G, G-C, or C-F. No exceptions.

The Complete Interval Map

Select an interval below to see its shape across the entire fretboard. The root and the target note are color-coded. Look at any pair on any string group - the geometric relationship is identical.

The Shape Table

Key Shapes to Memorize

Perfect 4th = Same Fret, Next String

This is the defining shape of fourths tuning. The tuning interval itself becomes a zero-effort reach. Just barre straight across.

Minor 7th = Same Fret, Skip a String

Two perfect 4ths stacked. Same fret, two strings apart. This shape is the backbone of shell voicings.

Octave = 2 Frets Up, Skip a String

Always the same diagonal. In standard tuning, octave shapes change at the G-B string boundary. Here, one shape rules everywhere.

Practice

Start with the perfect 4th (same fret, next string) and the octave (2 frets up, skip a string). Play the root on any fret, find the interval, then move the root somewhere else and confirm the shape holds. Once those are automatic, work through 3rds and 5ths. The goal: see any interval as a single geometric relationship you can place anywhere.