Music Theory by Justin Guitar

Music Theory by Justin Guitar

How Music Works on Fretboard

294 ratings
31 reviews
Free
In-App PurchasesWith Ads

Details

  • Released
  • Updated
  • October 7, 2025
  • June 24, 2026

Features

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About

This app transforms music theory into practical guitar skills through interactive lessons and fretboard exercises. Learn to understand keys, scales, and chords, and apply new concepts instantly to your playing. Accelerate your musical journey and break through learning plateaus.

Guitar-first approach to theory
Interactive fretboard exercises
Practical application of concepts
Fretboard trainer for note memorization
Immediate feedback on progress
Systematic, progressive lessons
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What's New in Music Theory by Justin Guitar

0.9.1

June 24, 2026

Improvements: Under-the-hood updates to our subscription and redemption systems for a smoother experience. Bug Fixes: Fixed an issue that could cause the app to crash when opening certain redemption links. Resolved a visual bug where the close button was missing from certain screens.

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Subscription plans

Yearly subscription

Unlock the theory course

$79.991 Year
1 Year trial
How to cancel Music Theory by Justin Guitar subscription ⁉️

Events

Read more about Unit 3 content released

Unit 3 content released

Keys, progression, creativity

Jan 29, 2026 Feb 27, 2026

User reviews

Relaxing way to learn

I wanted to thank Justin and his team for teaching me so many things I wish I’d learned years ago. I have played guitar since I was a teenager - always felt that it was beyond me - maybe knock out a couple of standards at a pinch round a fire. I am working through Grade 2 on Justin Guitar currently and although I know the chords and so on the practical advice on technique and practice, combined with an entirely new understanding of the theory from the Music Theory app is making a 59 year old a substantially better guitarist. And I have really enjoyed the process - there is a level of calm that I appreciate in the presentation. I’ve jumped ahead for a taste of what is to come and gone back to revise what I need to consolidate. A completely brilliant full package for anyone who wants to properly make progress on guitar.
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Music Theory App Justin Guitar

As with all Justin Guitar products, this is awesome and super useful!

Best lessons I‘ve ever had. Easy learning. Great Job.

Sabine

Helpful!

I am using the other Justin Guitar app for about 5 months and am making good progress. I know something about music but want to know more so I can play better.

Expensive and unnecessary

Good content, well presented by Justin and easy to follow, I learnt from the free content but could not see how this was worth the early access £45 asking price let alone the actual £80 asking!

There’s just not enough current content and I can’t see how they will justify the price.

Being subscription seems strange, It’s not something I’m going to come back to constantly.

Why isn’t it included as a module for the main Justin app if you wanted it? And why isn’t it a one off price?

Maybe if it was a one off bolt on for the main Justin app and much cheaper, £20? I’d gladly buy it but as it’s a separate app, not much content and unsure about future content, and so expensive it’s a pass.
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Developer apps

FAQ

What does the Music Theory by Justin Guitar app do?

This app teaches music theory specifically for guitarists. It uses a guitar-first approach with interactive lessons and fretboard exercises to make complex theory practical and easy to understand for playing.

What are the key features of this app?

Key features include interactive lessons that combine bite-sized theory with hands-on fretboard exercises, a fretboard trainer to memorize notes and chords, and immediate feedback to ensure you're learning correctly. It focuses on practical application rather than abstract concepts.

How much does the Music Theory by Justin Guitar app cost?

The app offers full access through several subscription packages. These subscriptions unlock unlimited access to all published stages of the learning material.

What devices is this app compatible with?

The app is designed for iPhone and iPad. Minimum requirements include iPhone 6S or later, iPad (5th generation) or later, and iOS 15 or newer. It is not optimized for PC or Mac.

Who is this app best suited for?

This app is ideal for guitarists who want to move beyond just playing chords and tabs. It's for anyone who feels lost when discussing keys, scales, or chord progressions, and wants to understand the patterns in music to improve their playing, improvisation, and songwriting.