Alternate tunings have a reputation for mystery they do not deserve. A retune is a list of signed numbers — this string moves down two semitones, that one stays — and everything the new tuning does follows from that list: which chord the open strings spell, which shapes survive, where the grid bends. So this section treats tunings as derived data. The three below are the guitar's most-traveled retunes; every delta, every open-chord claim, and every voicing count on their pages is computed from the shared tuning libraries and pitch math, then re-verified in CI.
The three, at a glance
| Tuning | Strings (6th → 1st) | Strings moved | Open strings spell |
|---|---|---|---|
| Drop D | D A D G B E | 1 | — |
| DADGAD (Celtic) | D A D G A D | 3 | Dsus4 |
| Open G | D G D G B D | 3 | — |
A ladder, not a menu
The three make a natural sequence. Drop D moves one string and keeps 83% of your fretboard knowledge intact — start there. DADGAD moves three and turns the guitar modal: the open strings stop resolving and start droning. Open G also moves three but lands on a full major chord, which is a different instrument philosophically: one finger is now a whole key, and a slide is suddenly a sensible tool.
Each page shows the string-by-string delta table, what the open strings now spell, and how many curated voicings its chord library ships. For standard-tuning bearings while you explore, keep the fretboard explorer and the chord reference open in the next tab — and when a retune becomes a home, the resonator pages show what an instrument built permanently around open G looks like.