ChordU vs OtoTheory

ChordU identifies chords in audio and aligns them with musical notation. Users can also find a song on YouTube, copy its link and search for it in ChordU. A song may have simplified, advanced, bass or edited chord arrangements, as well as treble-clef and bass-clef note versions. Chord diagrams cover guitar, piano, ukulele and mandolin. On the website, users can obtain PDF chord and note sheets, MIDI files and synthesized notes in WAV format. MusicOnly mode provides controls for vocals, bass, drums and other instruments, and can export a mixed audio download. Local music uploads and MusicOnly for those uploads require Premium; Premium also permits chord downloads without a stated monthly limit. The Free plan has limited access, while Premium costs $5.00 per month. ChordU is available on Android, iOS and the web. Its terms limit song and chord use to personal, non-commercial purposes.

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.