OtoTheory

OtoTheory is a music-theory companion and progression builder for players and songwriters who want to develop ideas as well as analyze songs. It is strongest for iOS users who value a path from harmonic exploration to DAW-ready MIDI; the web edition is a narrower workspace.

Overview

OtoTheory brings progression building, chord analysis, playback and export into one product. That makes it a useful fit for beginners and self-learners who want theory alongside songwriting, and for more experienced composers sketching material for a DAW. Its breadth is less compelling if the main need is a full desktop workflow: Pro is iOS-only, and the web version has fewer grooves and presets.

Key features

The progression generator, reverse chord lookup and voicing explorer support both creating and understanding harmony. Chord playback and chart export help turn an idea into something to hear or refer back to. More than 50 progression presets and 19 groove patterns offer useful starting points, though presets are prompts to adapt rather than a substitute for shaping a progression to suit a song.

On iOS, the app analyzes imported audio or guitar and piano recordings on-device, identifying chords, key and song sections. This makes it useful for studying how a song is put together, not just composing from scratch. Users can also paste progressions from ChatGPT, Claude or Gemini for Roman numeral analysis and playback with grooves. OtoTheory AI suggests chords through three stated lenses—feel, theory and emotion—adding another route for developing a sketch.

Pro MIDI export offers Groove, Groove + Theory and Chords Only modes, with BPM, section markers and chord names. The maker says exports work with Logic Pro, Cubase, Ableton and other DAWs. That detail makes the export more than a bare chord list, but it is gated behind Pro or Lifetime. Pro also adds exclusive grooves, unlimited saves and iCloud sync. Sketches otherwise stay on the device; web sketches use browser localStorage, so the web version is not a shared cloud workspace.

Pricing

The Free plan costs nothing and includes the iOS app with three local sketch saves. MIDI and audio export are unavailable, so it works for trying the creative tools but not for building an export-ready library or moving material into a DAW.

Pro is iOS-only, with monthly or annual billing; the annual plan is $49.99/year and includes a 7-day free trial. It unlocks unlimited MIDI and audio export, unlimited saves, iCloud sync, and Pro-exclusive grooves. The monthly price is $5.99/mo. Pro is the practical choice for regular iOS users who need ongoing exports, though its platform restriction rules it out for anyone who needs the paid workflow on web or desktop.

Lifetime costs $99.99, paid once, billed as a one-time purchase, and includes all Pro features forever on iOS. Unlimited exports, saves and iCloud sync make it a fit for committed users who prefer a single purchase over a recurring plan. It does not change the iOS-only limitation.

Platforms

OtoTheory is available on iOS and web, but the platform experience is uneven by design: the web version has a subset of iOS features and limited grooves and presets, while Pro is confined to iOS. Pro users can optionally sync sketches through iCloud, using Apple CloudKit’s encrypted infrastructure; exported MIDI can be sent to a Mac with AirDrop. The privacy policy says communications use HTTPS and that personal data is not sold.

Who it's for

OtoTheory suits guitar, bass and keyboard players, songwriters, composers, beginners and self-learners who want to explore harmony and analyze songs in the same tool. It is best for people willing to make iOS their primary workspace. Web-first users, or those who need Pro on a desktop platform, should look elsewhere.

Pros and cons

Pros: Analysis, progression generation, reverse lookup and voicing exploration span both songwriting and learning.

Pros: MIDI export includes groove and theory options plus tempo and section information, useful for carrying an arrangement sketch into a DAW.

Pros: Lifetime offers the full Pro feature set for a one-time $99.99, paid once purchase.

Cons: Free users get only three local saves and no MIDI or audio export, limiting its value as a continuing workspace.

Cons: Paid features are iOS-only, and the web version has fewer grooves and presets.

Cons: Web sketches are stored in browser localStorage, unlike the optional iCloud sync available to Pro users on iOS.

Alternatives

For a broader comparison, see Chord Finder Software.

ChordU is a freemium alternative on Android, iOS and web, with a $5.00 per month Premium plan that includes uploads, MusicOnly mode and downloads; consider it if cross-platform access and those features matter more than OtoTheory’s theory and progression workflow.

HarmonyBuilder is a paid option for Linux, macOS and Windows, with a Basic plan at $14.00 per month for four-part score writing, Chord Grid, playback and MIDI export; it suits readers who need desktop score-writing tools.

Chordio is available on iOS and macOS, with a free download that includes built-in sounds, an on-screen keyboard, every workspace and real-time MIDI chord detection; choose it if those features and Mac availability are the priority.

Harmony Pro is a free alternative for macOS, web and Windows.

Reverse Chord Finder Pro is a freemium iOS and macOS option with personal monthly pricing at $1.99 per month and family monthly pricing at $2.99 per month; it is worth considering for a more focused reverse-chord lookup need.

Tonaly is a freemium iOS and macOS alternative; its listed one-time purchases include 80+ Scales for $3.99 and PDF lead sheet export for $5.99, suited to readers who want those specific add-ons.

Autochords is a freemium iOS app whose free tier leaves some progressions to PRO; consider it if an iOS-only progression tool is enough.

Chord ai is a freemium Android and iOS option with unlimited free use stated for its basic features; consider it if that mobile availability and free-use model better fit your needs.

Verdict

Choose OtoTheory if you want one iOS-centered workspace for analyzing songs, exploring progressions and exporting MIDI to a DAW. Its main advantage is the breadth of that creative workflow; its main drawback is that the useful paid workflow, including unlimited exports and saves, does not extend beyond iOS.