Music Theory Guide — Guitar Chord Namer, Chord Progressions & Fretboard Scale Finder
Music Theory Guide is a free, interactive tool for guitar, bass, ukulele, mandolin, and banjo players. Name any chord you play, explore the chords that belong to a key, and map scales across the whole fretboard — all in your browser, with no sign-up.
Name any chord
Tap notes on the fretboard or type a chord name and the Chords tab identifies it instantly, including inversions and slash chords, and lists every note in the voicing.
Explore chords in a key
The Progressions tab shows the seven diatonic chords for any key with their Roman numeral functions, so you can build progressions that stay in key.
Map scales on the fretboard
The Scales view lights up every position of a scale across the neck, ranked from the most common shapes, on any of the five instruments and in standard or alternate tunings.
Frequently asked questions
How do I name a guitar chord?
Open the Chords tab, tap the notes on the fretboard or type them, and the chord name appears in real time.
What are diatonic chords?
They are the chords built from the notes of a single key. The Progressions tab lists all seven for any key you choose.
What instruments does it support?
Guitar, bass, ukulele, mandolin, and banjo. Pick one in Settings and the fretboard, chords, and scales adapt to it, including re-entrant ukulele tuning and the 5-string banjo's short drone string.
Does it support alternate tunings?
Yes — Standard, Drop D, DADGAD, and open D/G/E/C/A tunings are all supported.
Is it free?
Yes, completely free with no sign-up or download.