Guitar, bass, and ukulele are all fretted string instruments, and they all use the same basic chord diagram format — but students who study more than one often treat each instrument's diagrams as a brand new system to learn. They're not. Once the format clicks on one instrument, it transfers almost entirely to the others. The differences that remain are small and worth naming explicitly, so they don't cause confusion later.
The shared format
A chord diagram represents the fretboard as a small grid: vertical lines are strings, horizontal lines are frets, and the nut (or a fret number) marks where you are on the neck. Dots show where fingers go, numbers below often indicate which finger, and an "X" or "O" above a string means mute or play open.
- Vertical lines — one per string, arranged low-pitch string on the left in most published diagrams for guitar and bass
- Horizontal lines — frets, read top to bottom, headstock at the top
- Dots — where a fretting finger presses down
- X / O — string is muted / played open
That's the entire system. Everything else is just how many strings are on the grid.
Where instruments actually differ
Guitar (6 strings)
Standard tuning, low to high: E A D G B E. Diagrams show six vertical lines. This is the format most chord charts default to, since it's the most commonly published.
Bass (4 strings)
Standard tuning, low to high: E A D G — the same as the lowest four guitar strings, just an octave lower and without the top two. Bass chord diagrams are less common in practice since bass typically plays single notes, but the same grid logic applies when reading double-stops or chord voicings.
Ukulele (4 strings)
Standard tuning, low to high: G C E A — and this is the one genuine trap. The G string is tuned higher than the C string (this is called "reentrant" tuning), which means ukulele string order doesn't follow the same low-to-high logic guitar and bass do. The diagram format still works the same way — it's the actual pitches behind the grid that behave differently. This is worth internalizing early so a "C shape" on ukulele isn't mistakenly assumed to relate to guitar's C shape the way ukulele's G, C, E, or A open strings might suggest.
Why learning it once matters
The actual skill being built here isn't "guitar chords" or "ukulele chords" — it's reading a grid that represents a fretboard, which is a permanent, reusable skill. Once that's automatic, adding a new fretted instrument to your practice is mostly about learning new shapes, not learning a new reading system from zero.