OtoTheory - Chord Progression

Write chord progressions that hold together musically, without studying theory first.
Choose a key, choose a preset, and it plays immediately with drums, bass and keys behind it.
Then replace chords while the loop runs until it becomes your own.

Or start from sound: detect chords from your own audio, or from a quick recording of your playing. The result is editable, so use it as a draft for learning a part by ear, or turn a recorded idea into a progression.

Free to start.

HOW IT WORKS

1. Choose a key and scale. Only the chords that fit are offered.
2. Choose a preset, place chords yourself, or detect them from your own audio.
3. Press play. A full backing arrangement starts.
4. Replace any chord while it plays, and keep what works.

WHAT YOU GET FREE

- Chord Progression Builder
All 12 keys and every scale. Tensions and slash chords included. Auto-loop, BPM 40-180.

- Chord Detection
From an audio file or your own recording. Correct anything the detection missed and keep building from there. Free to try, and unlimited with Pro.

- Stem Separation
Split an imported song into four parts (vocals, drums, bass and other) and play just the parts you want to hear. All on-device. Works on iPhone and iPad with an A14 Bionic, M1 or later chip.

- Playback Tools for Learning by Ear
Play an imported song at 0.75x or 0.5x without changing its pitch. Use Repeat to loop just the bars you select, Pitch to shift the key in half steps, and EQ to bring out low or high sounds.

- 60+ Progression Presets
Pop, Rock, Jazz, Blues, Ballad and more, all free.

- 12 Groove Styles
Straight, Bounce, Strum, Piano, Shuffle, Pulse, Lo-Fi, a sustained-chord mode for the harmony, plus 6/8 and 12/8 ballad and rock.

- Chord Import
Ask any AI chatbot for a song's chords and paste them in: instant analysis and playback.

- Suggestions
OtoTheory proposes chords that fit the key, the scale and the chords around the slot you are editing. All come from music theory, so the progression holds together.

- Key & Scale Analysis
Auto-detect key and scale, with fit % and degree notation (I, IV, V).

- Fretboard & Keyboard
Guitar, bass and piano views. Chord tones light up in real time as the progression plays. Tap a note to hear it.

- Section Management
Verse, Chorus, Bridge, with repeat counts per section.

- Capo Suggestions
Find easier shapes for acoustic guitar.

- 3 Local Saves (sketches and detected songs combined)

PRO

- Unlimited Chord Detection and Recording
The heart of Pro. Detect from your own audio, or record yourself and detect from that, as often as you like.

- Unlimited Saves + iCloud Sync
Keep every idea, not just three. Sync between iPhone and iPad, and carry it to a new device.

- 38 More Groove Styles (50 in all)
City Pop, Neo-Soul, Bossa Nova, Lounge Jazz, Amapiano, Trap, Afrobeats, Reggaeton, Salsa, Gospel, Arena Rock and more, plus 6/8 and 12/8 feels.

- MIDI Export
A readable chord track, guide tones, a bass track and section markers. Kick, snare, hi-hat and each percussion instrument arrive on separate tracks, so you can rebalance, swap samples or re-quantize one without touching the rest. Tested in Logic Pro, Cubase and Ableton Live.

- Audio Export
Groove-backed audio for video and social posts.

- No House Banners
The in-app promotional banner is gone.

Pro is monthly, yearly or a one-time purchase. Prices are shown in the app.

WHO IT IS FOR

Guitarists who want to write songs before studying theory.
Producers sketching pre-production before opening a DAW.
Players who want scale guides to solo over their own changes.

FAQ

Q: Do I need to know music theory?
A: No. Choose a key and scale, and only the chords that fit are offered.

Q: What does Pro add?
A: Mainly unlimited chord detection: the free tier has a cap, Pro has none. It also adds unlimited saves with iCloud sync, 38 more grooves, and MIDI and audio export.

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