Before you learn scales or chords, you need to know where notes live on the fretboard. In fourths tuning, every note follows a single repeating logic - no exceptions.
The Chromatic Scale
Western music uses 12 notes. Starting from any note and moving up one fret at a time, you cycle through all 12 before arriving back at the same note one octave higher. That cycle is the chromatic scale:
The 7 natural notes - C, D, E, F, G, A, B - are the white keys on a piano. The 5 accidentals (the # notes) are the black keys. A sharp (#) raises a note by one fret. So C# is one fret above C, and F# is one fret above F. Notice that there is no sharp between E-F or B-C - those naturals are already one fret apart.
Each fret raises the pitch by one semitone - the smallest step in Western music. Move up 12 frets from any note and you arrive at the same note one octave higher. That is why fret 12 always matches the open string.
Open String Notes
In P4 tuning, the open strings are E-A-D-G-C-F from low to high. Here they are listed top-to-bottom, the same way tab and fretboard diagrams display them:
| String | Note | Interval above |
|---|---|---|
| 1 (highest) | F | -- |
| 2 | C | P4 (5 frets) |
| 3 | G | P4 (5 frets) |
| 4 | D | P4 (5 frets) |
| 5 | A | P4 (5 frets) |
| 6 (lowest) | E | P4 (5 frets) |
Every adjacent pair is exactly 5 semitones (a perfect fourth) apart. This uniformity is what makes P4 tuning special -- and why it is called "all fourths."
Natural Notes on the Fretboard
The fretboard below highlights all natural notes (C D E F G A B) in C major. Notice the pattern: the distance between any two notes is always the same regardless of which string you are on.
Key Insight
In P4 tuning, a note's position relative to any other note is always the same shape, on every string pair. If C is 3 frets above A on one string, it is 3 frets above A on every string. Standard tuning breaks this rule at the G-B boundary. P4 does not.