Fretted Chord Diagram Builder

How to use Fretted Chord Diagram Builder

Enter strings in the order you want to see them, using MIDI numbers for their unfretted tuning. Supply each relative-to-capo fret or null for muted, plus optional finger labels. A five-fret diagram marks open strings, mutes and pressed positions, while the report keeps source indexes and the exact resulting note number for every sounding string.

1. Use the example as the schema; replace its labels and entered model assumptions.
2. Enter strings in the order you want to see them, using MIDI numbers for their unfretted tuning. Supply each relative-to-capo fret or null for muted, plus optional finger labels. A five-fret diagram marks open strings, mutes and pressed positions, while the report keeps source indexes and the exact resulting note number for every sounding string.
3. Calculate, inspect the complete report and limitations, then copy the report or download the generated JSON or SVG artifact.

Good to know

• Two to eight strings; tuning MIDI integers 0–127, full capo 0–12, relative frets 0–24 or null. Capo plus relative fret must not exceed absolute fret 24. Every capo-open and sounding note must remain in MIDI 0–127, including muted-string capo-open tuning.
• Every finger entry is null or 1, 2, 3, 4 or T as a string. Muted and open strings require null. Positive frets must fit a five-fret window: start at 1 when all are at most 5, otherwise start at their minimum capped at 20 minus capo so empty rows never extend beyond accepted absolute fret 24. Dots sit between fret lines; this is a schematic, not physical neck spacing.
• Sharp/flat labels use C4=60 without key-aware enharmonic spelling. Mirror reverses drawn columns only. No chord database/name inference, fingering or barre validation, partial capo, audio, intonation or safe-instrument setup advice. The SVG has fixed 92 mm by 94 mm dimensions; labels are escaped and fitted.
• Local calculation with no upload, input persistence or outside lookup. Model JSON is limited to 30,000 characters and 10,000 values. Decimal quantities are strings with up to six places; count fields use plain JSON integers. Exact fractions are capped at 8,192 bits. The complete JSON output is limited to 1,000,000 characters; approximate numbers preserve their stored values. Unsupported states fail explicitly.