OtoTheory

OtoTheory is a chord-progression and music-theory workspace for guitar, bass and keyboard players, songwriters, composers and DAW users. It is best for people who want to understand a song and develop their own harmony in the same workflow. The strongest value is on iOS; the free tier and web edition impose meaningful limits for anyone who needs regular exporting or the full preset library.

Overview

OtoTheory covers several stages of writing: finding chords, examining a recording, trying alternate voicings, building a progression and moving the result into a DAW. Beginners and self-learners get theory-oriented guidance, while more experienced composers can use grooves, presets and MIDI output to turn sketches into arrangements. Its platform split is important: the web app is a reduced version, and Pro features are restricted to iOS.

Key features

The progression generator, reverse chord lookup, voicing explorer, chord playback and chord-chart export address both discovery and practice. More than 50 chord-progression presets and 19 groove patterns supply usable starting points instead of leaving every idea to a blank canvas. Playback makes it possible to judge a progression by ear, while voicing tools help players adapt it to guitar, bass or keyboard.

On iOS, song analysis works on imported audio or on a guitar or piano recording made on the device. It identifies chords, key and song sections, which is useful when learning how a reference track is organized or checking a newly recorded idea. You can paste progressions from ChatGPT, Claude or Gemini for Roman-numeral analysis and groove playback. OtoTheory AI proposes chords through the maker’s three-part approach of feel, theory and emotion; that is more useful for guided exploration than a basic chord dictionary.

Pro MIDI export offers Groove, Groove + Theory and Chords Only modes, with BPM, section markers and chord names. The maker says these files work with Logic Pro, Cubase, Ableton and other DAWs, so the feature is aimed at a songwriting workflow that leaves the app. AirDrop can move exports to a Mac. Optional iCloud sync on iOS keeps Pro sketches across devices, while free sketches remain local.

Pricing

The Free plan is suitable for trying the core tools or keeping a small number of experiments, but three saves and no export make it a poor fit for an ongoing production archive. Pro suits active iOS songwriters who prefer a recurring cost and need unlimited storage and export; its seven-day trial gives a short evaluation window. Lifetime costs more upfront but makes sense for long-term iOS users who would otherwise keep paying monthly or annually. None of the paid plans extend Pro to the web version.

Platforms

OtoTheory runs on iOS and the web. The web edition has a subset of iOS functions, including limited grooves and presets, so it works better for lighter exploration than as a complete replacement for the mobile app. Pro is iOS-only. Pro sketches can use Apple CloudKit-backed iCloud sync, while web sketches are stored in browser localStorage. Communications use HTTPS, and the maker says it does not sell personal data.

Who it's for

Choose OtoTheory if you are a beginner, self-learner, songwriter or composer who wants theory explanations alongside practical progression building. Guitar, bass and keyboard players benefit from the instrument coverage, chord playback and voicing exploration. DAW users have a clear reason to pay for Pro when BPM-aware MIDI with section markers is part of their process. It is less suitable for someone who needs full functionality in a browser, Android support or a generous free export tier.

Pros and cons

Pros

• Broad writing workflow: analysis, generation, voicings, grooves and export sit in one product.
• Useful song analysis: iOS can identify chords, key and sections from audio or a guitar/piano recording on-device.
• DAW-oriented export: Pro MIDI modes include BPM, section markers and chord names.
• Long-term option: the Lifetime plan avoids recurring payments while retaining Pro features.
• Clear data controls: sketches stay on-device or in the user’s iCloud account on iOS, and web sketches stay in localStorage.

Cons

• Free plan is restrictive: only three local saves and no MIDI or audio export limit serious free use.
• Platform inequality: the web version has fewer grooves and presets, and Pro cannot be bought for web use.
• Paid access is iOS-dependent: Android users cannot use the mobile app, while desktop users receive the reduced web experience.
• Trial is brief: seven days may be tight for evaluating a complete songwriting workflow.

Alternatives

Pick ChordU instead if you need Android support, web access and a $5.00-per-month Premium plan with uploads, downloads and MusicOnly mode. Chord Analyser is a better choice for a straightforward Android or iOS chord-analysis app without a free trial. Choose Chordio for iOS and macOS workspaces with built-in sounds, an on-screen keyboard and real-time MIDI chord detection. ChordSequence suits users who want a free Android/web tool with no paywall or usage limit and WAV and MIDI export. Harmony Pro is the free macOS, Windows and web alternative. Autochords is a lower-cost iOS option when free app features and selected Pro progressions are enough. Chord ai fits Android or iOS users seeking unlimited basic free use and a $9.00 monthly advanced tier. ChordProgressions.org is the simplest choice for a free, browser-based studio.

Verdict

OtoTheory is a strong choice for iOS-based songwriters, players and composers who want analysis, theory-led exploration, grooves and DAW-ready MIDI in one place. Its main reason to choose it is the unusually complete progression-to-export workflow. Look elsewhere if you need Android, full browser parity or meaningful free exports; the three-save cap and iOS-only Pro access quickly become practical constraints.