Reverse Chord & Scale Lookup for Guitar — Find Chord by Notes, Identify Scale

TL;DR — The free reverse chord & scale lookup at myguitartutor.com goes from notes to chord/scale names — the opposite of a regular chord lookup. Drop in notes from the fretboard or a chromatic picker, get every chord and scale that fits, ranked by best match. Built for ear training, arrangement transcription and theory teaching.

The traditional chord-lookup flow is: you know the chord, you want the diagram. The reverse-lookup flow is harder and more interesting: you have a sound (or a set of notes on paper) and you want to know what it is. This is the everyday work of arrangement, transcription, and ear-training — the things that turn a competent player into a musician.

The free reverse chord & scale lookup is built specifically for that direction of work.

What it is

A browser-based tool that takes a set of notes and returns every chord and scale they could form:

• Two input methods — fretboard picker (click fret positions) or chromatic note picker (click note names on a 12-note grid).
• Chord results — every chord that matches the input notes, ranked by best match. Includes inversions, extensions, and slash-chord interpretations.
• Scale results — every common scale that fits the input notes (major modes, pentatonic, blues, harmonic minor, exotic). Best match ranked first.
• Live updates — add or remove a note, the results recompute immediately.
• Audio feedback — hear the notes you’ve added, in order or as a chord stack.
• Cross-link to encyclopedia — click a chord result to jump straight to its encyclopedia page with the canonical voicing.
• No signup, no ads, no usage limits.

How to use it

Three steps, depending on what you’re trying to identify:

Identifying a chord by ear

1. Open the reverse lookup.
2. Listen to the chord you’re trying to identify. Pick out the lowest note (the root or bass note) by humming or playing it on guitar.
3. Add notes to the picker one at a time as you identify them. The chord list narrows with each addition. By the time you’ve heard four distinct notes, the answer is usually unambiguous.

Identifying a chord from a written source

1. Read the notes from the chord chart or score (e.g. “D F♯ A C”).
2. Click the matching note names on the chromatic picker.
3. Read off the chord name — D7, in this case, plus several inversions and upper-structure interpretations.

Identifying a scale from a phrase

1. Pick the notes of the phrase one at a time (typically 5–7 distinct notes).
2. Read the scale matches — for 5 notes you’ll usually see multiple pentatonic and modal candidates; for 7 notes one match typically dominates.

Pro tips for tutors

Use reverse lookup for arrangement transcription

When a student brings a song they want to learn that doesn’t have a published tab, work through the song one chord at a time. Listen, isolate the notes you can hear, drop them into the lookup. The tool finds the chord; you’ve just transcribed a measure. Over a few sessions, the student internalises the chord-identification process and starts doing it by ear.

Pair with ear training

Play four notes on the guitar (don’t show them what you played). The student listens, identifies the notes by ear, builds the set in the lookup, names the chord. Verify against the lookup’s output. This is one of the most concrete ear-training exercises you can set, and it produces measurable progress over weeks.

Use it for chord substitution exploration

Build a chord (say, C major: C E G), then start adding notes from outside the chord. C E G B → Cmaj7. C E G B♭ → C7. C E G A → C6. C E G D → Cadd9. The student sees in real time how a chord transforms as upper extensions get added — which is one of the cleanest ways to teach extended chord theory.

Use the scale matcher for solo analysis

When transcribing a guitar solo, pull out the notes of a phrase and run them through the lookup’s scale matcher. The matched scale tells you the modal/melodic palette the original guitarist was thinking in — which is gold for both teaching and your own improvisation.

Where it fits in the teaching workflow

The reverse lookup lives in the theory/listening block and the repertoire block of a structured lesson:

1. Plan the lesson with a lesson planner — block out theory/listening time and the specific arrangement work for the repertoire block.
2. Use the lookup during arrangement work to identify ambiguous chords or analyse the scale a riff draws from.
3. Set ear-training homework based on the same workflow — three chords per week the student has to identify by ear, log on the practice log.
4. Track ear-training milestones on the student progress tracker.

The pillar pieces: How to plan a guitar lesson, How to track guitar student progress, How to get guitar students to actually practice.

Tools that pair with the reverse lookup

The reverse lookup is one of seven free browser tools for guitar tutors:

• Chord encyclopedia — the forward direction. Once the lookup identifies a chord, jump straight to the encyclopedia page for the canonical voicing.
• Chord chart generator — build a custom diagram for the chord you’ve just identified.
• Chord progression builder — drop the identified chord into a progression, hear how it functions.
• Scale generator — visualise the scale the lookup identified.
• Metronome — for tempo-graded ear-training work.
• Tuner — before any ear training (out-of-tune notes mess up identification).

Try it now

The free reverse chord & scale lookup opens instantly. Bookmark it for arrangement sessions, ear-training lessons, and chord-substitution explorations.

If you’re running a tutoring practice that’s outgrown a folder of free tools, our bespoke teaching platform embeds reverse lookup directly into each student’s chord and progression workflow — so identifying and saving chords becomes a single tap, in their app, on your domain.