Chord Analyser vs OtoTheory

Chord Analyser identifies chords entered as notes on a piano keyboard or fretboard, then shows playable positions for the selected chord. Its library recognizes over 3,500 chords, and its chart editor supports measures, subdivisions, repeats, time and key signatures, playback, auto voicing, and PDF export. The free version costs nothing, has no time limit or ads, and includes one chord chart. More charts require the full version, a one-time payment whose price comes from the app store. That version adds eight instruments, open tunings, MIDI input, unlimited charts, and chart transposition. Microphone recognition is an Android-only beta; it identifies one chord at a time and may struggle on older phones. The maker says audio transcription happens on-device without an internet connection. The app is available for Android and iOS and is described for learners, composers, performers, and musicians who play across instruments.

OtoTheory is a chord progression builder and music theory companion for guitar, bass, and keyboard players, songwriters, and DAW users. Its iOS app can identify chords, key, and song sections from imported audio or an on-device guitar or piano recording. Users can paste progressions from ChatGPT, Claude, or Gemini for Roman numeral analysis and playback with grooves. The app lists 19 groove patterns and more than 50 progression presets; OtoTheory AI suggests chords using musical feel, theory, and emotion. Pro exports MIDI in Groove, Groove + Theory, or Chords Only modes, including BPM, section markers, and chord names. The maker says those exports can be used with Logic Pro, Cubase, Ableton, and other DAWs. OtoTheory is available on iOS and the web, but the web version has fewer features and Pro is iOS-only. The free iOS plan allows three local sketch saves and excludes MIDI and audio export. Pro is listed from $5.99/mo; its annual plan is $49.99/year, and Lifetime costs $99.99 once.