OtoTheory vs Reverse Chord Finder Pro

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.

Reverse Chord Finder Pro identifies chord names from two or more selected notes. Notes can be entered through a piano, string-instrument layout or music-score notation. The app includes more than 100 chord types and can play results as block chords or arpeggios. Partial matching helps isolate passing melody notes, while Favorites stores identified chords. String layouts support three to twelve strings, left-handed setups and capo options. Music Score mode offers treble and bass staves in all 12 major and minor keys. Users can inspect intervals, chord structure and naming options. Supported instruments include piano, guitar, bass, ukulele and other three- to twelve-string instruments. It runs on iOS and macOS; listings require iOS 15.6 or later and macOS 13.0 or later on Apple M1 or later. Pricing includes a seven-day trial, with personal, family and lifetime plans.