Chord Library vs OtoTheory
Chord Library
chord-library.com
OtoTheory
ototheory.comSide by side
| Figure | Chord Library | OtoTheory |
|---|---|---|
| Price from | — | Free |
| Free plan | — | Yes |
| Free trial | — | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| iOS | — | Yes |
| Plans published | 2 | 3 |
| Spec score · Chord Finder Software | 7.5 (#17) | 7.8 (#10) |
| Support | The contact page invites questions, feedback, and data requests and says the team will respond as soon as it can. | The support page lists [email protected] and says it typically responds within two business days, excluding weekends and holidays. |
Plans
Chord Library
- Guitar Chord & Scale Reference PDF$9, paid once
- Ukulele Chord & Scale Reference PDF$9, paid once
In their own words
Chord Library
Chord Library has no write-up on Specifiction yet; its figures are above.
OtoTheory
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.