The A shape is the open A chord — three notes in a row on the 4th, 3rd, and 2nd strings, root on the open 5th — promoted to the most-used barre form in rhythm guitar. Barre with the index, stack the triple with three fingers (or lay the ring finger across all three), and the 5th-string root under the barre names the chord.
Where it starts, for every root
Recomputed from the voicing library: the A shape's major form for each of the twelve roots, with its starting fret and exact frets (x = muted). The geometry is identical in every row — only the address changes.
| Root | Starts at | Frets (6th → 1st) |
|---|---|---|
| A | fret 1 | x–0–2–2–2–0 |
| A# | fret 1 | x–1–3–3–3–1 |
| B | fret 2 | x–2–4–4–4–2 |
| C | fret 3 | x–3–5–5–5–3 |
| C# | fret 4 | x–4–6–6–6–4 |
| D | fret 5 | x–5–7–7–7–5 |
| D# | fret 6 | x–6–8–8–8–6 |
| E | fret 7 | x–7–9–9–9–7 |
| F | fret 8 | x–8–10–10–10–8 |
| F# | fret 9 | x–9–11–11–11–9 |
| G | fret 10 | x–10–12–12–12–10 |
| G# | fret 11 | x–11–13–13–13–11 |
Using it
The A shape is position 2: it picks up exactly where the C shape ends, and hands off to the G shape above it. Its great virtue is economy — the whole chord lives inside three frets, the muted 6th string keeps the low end clean, and the same footprint carries its minor, seventh, and m7b5 cousins with one-finger changes (compare them on any root's page in the chord library).
Start from open A, slide the form to fret 3 for C major, fret 5 for D — the table above is the complete itinerary. When a song lives between frets 3 and 7, this is usually the shape doing the work.