Interactive guitar & music theory platform

Stop reading about guitar. Start playing it with tools that actually think.

Twelve interactive apps, a notated music library of over 2,400 pieces, video courses, a full podcast archive, curated downloads, and a working community — built for real guitarists, from CAGED-stuck beginners to jazz pros hunting fresh voicings. One login. One price.

Coming soon
Opening shortly
The platform is in final testing. Everything below is built and working — scroll on to see exactly what you'll get.

Every tool a serious guitarist needs — in one place, for less than a coffee a week.

One platform. Every tool. Every level.

Reference, explore, compose, practise — twelve interconnected apps that speak the same language, built by a working professional across forty years of playing, teaching and writing.

GMI Premium — the complete workshop for the progressing guitarist
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The Suite

Twelve apps, plus Thomas. One platform. Zero fluff.

Every app in GMI Premium was built by working guitarists to solve a real problem — not to look pretty in a marketing screenshot. Click any infographic below to see the app in detail.

Chord Lab infographic Partly free

Chord Lab

Explore every voicing on the guitar — Drop 2, Drop 3, Drop 2+4, shells, extended. Hear it played, see it on the fretboard, understand why it works. Then build a progression from the shapes you are looking at and play it back — open at every tier.

Chord Architect infographic Pro

Chord Architect

The full catalogue of chord qualities — every extended and altered colour a jazz or contemporary player reaches for. Filter by voicing type, see each shape laid out across the neck with correct fingerings, send it on to another app.

Progression Lab infographic Pro

Progression Lab

Build a chord sequence and hear it voiced with real voice leading — each chord chosen to move smoothly into the next. All keys, all voicing families, PDF and PNG export.

Structure Lab infographic Pro

Structure Lab

Polychords, upper structures, and the colours above the chord. Built directly on the material in Ged's book Upper Structures, Synonyms & Slash Voicings For Jazz Guitar.

Sight Reader infographic Partly free

Sight Reader

Read with intent. Build real reading fluency across three literacies — single-line, rhythm chart, chord-melody. Self-hosted Verovio 6.2.0 engraving. The same 700+ pieces a free account can read. All eight grades on Pro.

Practice Studio infographic Pro

Practice Studio

Practise against real backing tracks with bass and drums played by professionals. Record yourself, get scored on timing, tempo and pitch accuracy, and watch your progress build session by session.

GMI Guitar Library infographic Partly free 📚

GMI Library

Over 2,400 notated pieces spanning four centuries — classical, folk, traditional and jazz, all graded 1–8. A free account opens 700+ of them: every piece at Grades 1–3, plus 400+ Guitar Loot arrangements free at any grade. The full library on Pro. Notation, playback, one-tap handoff to Sight Reader.

Harmonic Universe infographic Free to all

Harmonic Universe

See how every key, chord and scale connects. A visual map of harmony you can navigate, zoom into, and send any node straight to Chord Lab.

Sketchpad infographic Partly free

Sketchpad

The workspace that ties it all together. Drop in chord diagrams, notation, images and notes. Arrange, snap, print, share — your ideas, one page.

Diatonic Key Builder infographic Pro

Diatonic Key Builder

Every chord that lives inside a key — laid out, playable, hearable. The fastest way to internalise how songs actually work.

Theory Glossary infographic Free tier

Theory Glossary

Every term, every concept, plain-English explanations with playable examples. The reference you'll actually use.

Cycle Wheel infographic Free tier

Cycle Wheel

The cycle of 4ths/5ths as a working tool. Trace root movement, explore dominant gravity, build turnarounds, feed the results straight into Progression Lab.

Ask Thomas Balfour infographic On every screen 🎩

Ask Thomas Balfour

Your teacher, on every screen. GMI's resident AI music guide — context-aware, never generic, never patronising. Answers real theory questions and explains any feature, wherever you are in the platform.

Beyond the apps

Courses, masterclasses, podcasts, community.

The apps are the engine. GMI Premium is a full learning platform behind them — a decade of filmed teaching, a podcast archive, downloadable resources, and a working community of guitarists.

Free to all members 🎓

Video Courses

Drop Two Voicings — 13 lessons, around thirty hours of study, companion to Ged's book. Plus How To Play Barre Chords, Beyond Barre Chords, Minor Pentatonic Scales, Fingerstyle Guitar Techniques and Advancing Guitar. All free with a free account.

Pro 🎬

Pro Masterclasses

Triadic Inversions · Creative Arpeggios · Harmonise & Arrange A Jazz Standard · Overjoyed, a full solo arrangement · Streets Of London chord melody · The Theorbo Masterclass, filmed at Edinburgh Napier University. Video, PDF and audio together.

Free to all members 🎸

Individual Lessons

Standalone deep dives — right-hand technique, three-note-per-string fretboard work, finger stretching, and a 28-minute tapping lesson with a 45-page book and backing tracks. Nine scale lessons from chromatic through to diminished. A Nigel Clark jazz chord-melody lesson with notation and play-along audio at three speeds.

Free to all members 🎙️

The GMI Podcast

61 episodes with working musicians, teachers and industry figures. The complete back catalogue, no limits — start anywhere.

Free to all members ⬇️

Books, Downloads & Email Courses

Backing tracks, chord charts, scale references and notation PDFs alongside every lesson. The 22 Hit Songs and 33 Hit Songs email courses. GMI author books and downloads, with bonus book resources on Pro.

Free to all members 👥

The Community

A working space, not a dead Facebook group. Introduce yourself, post what you're working on, ask Thomas a theory question, and get answers from other guitarists and directly from Ged. Pro and Founding Members also get the Founding Members Lounge.

Pricing

Start free. Go Pro when you're ready.

Free gets you inside straight away — no card. Pro unlocks everything. The first 200 members lock £9.99 a month for as long as they stay.

Free
£0
Forever — no card needed
  • Chord Lab — triads, all string sets
  • Harmonic Universe — fully open
  • Theory Glossary — full reference
  • Ask Thomas — AI music guide
  • Build & play a progression in Chord Lab
  • Cycle Wheel — all but the Turnarounds builder
  • Guitar Library — 700+ pieces, 29% of the catalogue
  • Sight Reader — the same 700+ pieces
  • Sketchpad — three chords on a canvas
  • All free video courses
  • 61 podcast episodes, full archive
  • Post & comment in the community
  • Extended & altered voicings
  • Progression Lab, Structure Lab
  • Diatonic Key Builder
  • Practice Studio
  • Pro masterclasses
Coming soon
Pro
£14.99
Per month · cancel anytime
or £129/year — save £51
  • Everything in Free, plus…
  • Chord Lab — every chord type
  • All voicings — Drop 2, 3, 2+4, shells
  • Chord Architect — full catalogue
  • Progression Lab — voice leading engine
  • Structure Lab — polychords & upper structures
  • Diatonic Key Builder — all 12 keys
  • Cycle Wheel — Turnarounds builder
  • Sketchpad — save unlimited pages, PDF/PNG export
  • Practice Studio — full access & progress tracking
  • Sight Reader & Library — Grades 1–8
  • All Pro masterclasses
  • Book resources & bonus downloads
Coming soon
Teacher
In development
Pricing to be announced
  • Everything in Pro
  • Lesson-planning tools
  • Assign practice to students
  • Share Sketchpad pages 1-to-1
  • Full feature set — TBC
  • Pricing & annual option — TBC
Coming soon
⬡ Cancel anytime · No card needed to start free

Stop guessing.
Start playing.

Free accounts open at launch — no card, sixty seconds, and you're inside. Founding places are limited to the first 200.

Coming soon