The Smart Chord Diagram translates music theory into visual guitar fingerings. When you select a chord in the Harmonic Tree, the diagram shows you exactly where to place your fingers on the fretboard. It intelligently finds playable voicings, considering fret position, hand reach, and string tuning — all in real-time.

Open strings appear as non-filled green circles. Muted strings show a red 'X'. Fretted notes are colored dots — orange for the root note, green for other chord tones — with finger numbers inside. When three or more strings share the same fret, a barre line appears with a 'B' marker, just like real guitar chord charts.

The diagram works with any tuning — standard, drop D, open G, or custom. Change the fret position from 0 to 24, and the diagram automatically adjusts to show barre chords and higher voicings. The hand reach setting controls how many frets the algorithm can span, creating realistic fingerings. String count adapts for guitar, bass, ukulele, or any stringed instrument.

The chord diagram runs in the Electron app and receives fretboard data directly from the TMA device. The same tuning, fret position, and reach settings that control the hardware fretboard display also drive the software diagram. A chord voicing algorithm finds the optimal fingering by prioritizing root notes, then fifths, then thirds, while avoiding unplayable fingerings.

Guitarists can learn new chord shapes instantly. Bass players see accurate fretboard positions for any tuning. Music educators can demonstrate chord voicings in real-time. Composers can visualize chord shapes while writing progressions. The Smart Chord Diagram bridges the gap between theoretical harmony and physical instrument.