Daniel Murphy
Guitar Theory Educator & Audio Analysis Developer | Founder, GuitarChordIdentifier.com
Every guitarist reaches a point where they play a chord shape they did not learn by name — a grip they discovered by accident, heard on a recording, or borrowed from another player — and wonder: what is that chord, actually? Naming a chord from its physical shape on the fretboard requires understanding the relationship between fret positions, string tuning, and interval theory. Most guitarists skip that step and stay in a world of shapes without names. GuitarChordIdentifier.com exists to close that gap.
My name is Daniel Murphy. I have spent years working at the intersection of guitar theory and audio analysis — studying how guitar chord voicings map to interval sets, how the same chord can appear in multiple inversions across the fretboard, and how browser-based audio analysis can identify simultaneously played notes from a microphone input and match them to chord names. These are not trivial problems. Polyphonic pitch detection — detecting multiple simultaneous fundamental frequencies from a single microphone — is significantly more complex than detecting a single voice frequency, and guitar chords add further complexity through inversions, open strings, and the non-standard voicings that characterise real guitar playing.
The tool on this site works in two modes. In fret input mode, you select the fret positions and strings you are playing, the tool extracts the pitch class set, analyses the intervals between notes, and looks up the matching chord name — including the inversion if the bass note is not the root. In microphone mode, the tool captures your guitar’s audio via the Web Audio API, performs polyphonic pitch detection to extract simultaneous fundamental frequencies, maps those to pitch classes, and identifies the chord. To understand exactly how both pipelines work, visit the How It Works page.
What I Research and Write About
Guitar Chord Voicings and Fretboard Theory The guitar fretboard is a grid of 144 notes across six strings and 24 frets — the same note can appear in multiple positions, the same chord can be voiced in dozens of valid configurations, and the same shape in different positions produces different chords. I research the mapping between physical fret positions and pitch classes, how chord quality is determined by the interval set within a voicing, and how inversion is identified by the bass note of the played chord. Understanding this mapping is the foundation of everything GuitarChordIdentifier.com does.
Polyphonic Pitch Detection in Browser Audio Detecting a single fundamental frequency from a monophonic source is well-documented in Web Audio API literature. Detecting multiple simultaneous fundamentals — as required for guitar chord identification from audio — requires a more complex pipeline: spectral peak extraction, harmonic series analysis to separate co-occurring fundamentals from their harmonics, and pitch class reduction to map detected frequencies to note names. I research the specific implementation challenges of polyphonic detection in the browser environment and document the accuracy and failure modes of the approach used on this site. The FAQ addresses the most common questions about why audio-based chord identification produces the results it does.
Chord Naming Conventions Across Guitar Contexts Guitar music spans classical, jazz, pop, blues, and folk contexts — and each applies different chord naming conventions for the same note sets. A note collection that a classical guitarist names as a Gmaj7/B (G major seventh, third in bass) might be described differently in a jazz chart or a pop lead sheet. I research and document these conventions, explaining where naming differences arise and how GuitarChordIdentifier.com handles ambiguous cases.
Inversion Identification and Bass Note Analysis Guitar chords are frequently played in inversion — with a note other than the chord root in the lowest voice. A G/B chord, a C/E chord, and an Am/C chord are all inverted voicings where the bass note identifies the inversion. I write about how inversion detection works, why it matters for chord naming accuracy, and what the limitations of bass note identification are when the lowest detected frequency is ambiguous.
Why I Built This
When I was looking for a browser-based guitar chord identifier that handled inversions correctly, documented its algorithm, and was honest about the limitations of polyphonic pitch detection — particularly for complex voicings and barre chords on a budget microphone — I found tools that returned a name with no explanation and no account of why the result might be wrong.
What I built is a tool that names chords from physical fret input or live audio, explains the interval basis for the identification, documents the inversion where applicable, and states clearly what the polyphonic detection pipeline can and cannot handle reliably.
Accuracy Standards
Every chord formula, interval definition, and audio analysis description on GuitarChordIdentifier.com is cross-referenced against established guitar theory and Web Audio API documentation. Chord identification accuracy figures are documented with specific reference to the detection mode (fret input vs microphone), the voicing complexity, and the audio quality variables that affect polyphonic pitch detection. For how microphone audio is handled during chord detection, see the Data Security page.
Tools on This Site
- Guitar Chord Identifier — guitarchordidentifier.com
Get in Touch
For content corrections, technical questions, or data requests, visit the Contact page or email directly: contact@guitarchordidentifier.com
Response times: technical and content questions within 48–72 hours. Privacy and data requests within 7 business days. GDPR requests within 30 days. CCPA requests within 45 days.
Daniel Murphy is the founder and sole author of GuitarChordIdentifier.com. For a full account of how content is researched and written, see the Editorial Guidelines. Last updated: June 2026.