OtoTheory - Chord Progression
Songwriting & Scale Practice
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
Import chord progressions via AI. Scale analysis, degree display, fretboard/keyboard chord tones, groove playback & MIDI export. Songwriting & music theory made easy.
OtoTheory is a chord progression builder. Create theory-correct progressions intuitively — no theory knowledge required.
Now with AI import: ask AI for any song's chords, copy & paste. Degree analysis, backing playback, and MIDI export — instantly.
Who Is This For?
Guitarists who want to write songs without theory
Players seeking scale guides for solos
DTM users needing pre-production tools
Acoustic players needing capo suggestions
Songwriters wanting chord substitution ideas
Bassists and keyboardists exploring chord tones
Free — All Creative Tools
▸ AI Chord Import
Ask AI for any song's chords, copy & paste. Instant analysis and playback.
▸ Chord Progression Builder
12-slot grid. Pick a key and scale — only correct chords appear. Tensions and slash chords included. Auto-loop, BPM 60-180.
▸ 15 Groove Patterns
All 15 grooves free. Edit chords in real-time while playing.
▸ 50 Presets
Pop, Jazz, Blues, Rock, Ballad — all 50 presets free.
▸ OtoTheory AI
Bridge, Substitute, Advanced modes. AI-powered suggestions to expand your ideas.
▸ Section Management
Verse, Chorus, Bridge. Set repeat counts per section.
▸ Scale Analysis
Auto-detect key and scale. Fit %, degree notation (I, IV, V).
▸ Fretboard & Keyboard
Guitar, bass, piano views. Chord tones highlight in real-time during playback. Tap to play.
▸ Capo Suggestions & 3 Local Saves
Pro — Unlimited Workflow ($2.99/mo)
▸ MIDI Export
Groove arrangement → MIDI. Chord Track, Guide Tones, Bass Track, section markers. Logic Pro, Cubase, Ableton ready.
▸ Audio Export
Groove-backed AAC files for videos and social media.
▸ Unlimited Export
No limits. *Free: 1/day via ad.
▸ Unlimited Saves + iCloud Sync
Sync iPhone & iPad. Transfers to new devices.
▸ Ad-Free
Why OtoTheory?
No Theory Required: Pick a key, select chords. Done.
Game-Like Editing: Swap chords in real-time while grooves play.
3 Visual Views: Guitar, bass, keyboard — chord tones highlighted during playback.
DAW Ready: MIDI export with groove arrangement. Phone to DAW seamlessly.
Acoustic Friendly: Capo suggestions for comfortable positions.
FAQ
Q: Need music theory?
A: No. Pick a key and scale — correct chords appear automatically.
Q: Free vs Pro?
A: All creative features free (15 grooves, 50 presets, all chords, AI, sections). Pro: unlimited export, unlimited saves + iCloud, ad-free.
Q: MIDI export?
A: Pro exports groove arrangement as MIDI with chord track, guide tones, bass, markers.
hello@ototheory.com
Privacy: https://ototheory.com/privacy
Terms: https://ototheory.com/terms
Build progressions and enjoy songwriting with OtoTheory.
more This update includes bug fixes and improvements to enhance your experience.
2.20.2 1d ago
■ New Foundations category
Clean, single-instrument backings (piano, guitar, bass and more) in whole-note, quarter, eighth, and sixteenth rhythms. With no extra ornamentation, they're perfect for checking how chords and scales sound, practicing or ear-training, and laying a foundation before you arrange.
■ New Neo-Soul groove
A Wurlitzer electric piano plays rich extended-chord voicings (9ths, 11ths, 13ths) for a smooth, feel-good funk-soul sound. Just lining up chords already sets the mood.
Some of the new grooves are Pro, but you can preview them by watching an ad. For full production in a DAW, Audio / MIDI export is available with Pro. Plus various minor improvements.
Feedback: support@ototheory.com
2.20.1 3d ago
A new piano-driven, high-speed rock groove, "Piano Rock," is now available.
It blends a piano playing shimmering tension chords, a rich choir, and power-chord guitars into an uplifting, anime-opening / emo-style sound. The piano arrangement is built so the harmony stays clear even at fast tempos: the right hand brings out the tensions while the left hand holds down a low foundation.
Piano Rock is a Pro groove, but you can also preview it by watching an ad. If you want to take it further in a DAW, Audio / MIDI export is available with Pro.
Plus various minor improvements and bug fixes.
Feedback: support@ototheory.com
2.18.0 6d ago
A new groove "Afrobeats" is now available — the 4th entry in the Loops category.
Afrobeats: a mellow West African Afropop groove featuring muted-guitar 16th-note cutting, a syncopated 3-3-2 kick, call-and-response congas, and a soft electric piano. Recommended BPM 95-110 — a relaxed, danceable groove that's ready to build in seconds.
Afrobeats is a Pro groove, but you can also preview it by watching an ad. If you want to take it further in a DAW, Audio / MIDI export is available with Pro.
Plus various minor improvements and bug fixes.
Feedback: support@ototheory.com
2.17.0 May 31
A new groove "Trap" is now available — the 3rd entry in the Loops category.
Trap: an Atlanta Trap groove featuring a deep 808 sub-bass, dark Kalimba stabs with tense voicings, half-time hand-claps, and shimmering hi-hat rolls. Recommended BPM 130-150 — a heavy, sunken half-time beat that's ready to build in seconds.
Trap is a Pro groove, but you can also preview it by watching an ad. If you want to take it further in a DAW, Audio / MIDI export is available with Pro.
Plus various minor improvements and bug fixes.
Feedback: support@ototheory.com
2.16.0 May 30
A new "Loops" category for loop-based beatmaking is now available — added to both chord progression presets and grooves.
[Presets] 7 loop-oriented presets for hip-hop, Lo-Fi, trap, Drill, Latin House, Phonk, and EDM: Lo-Fi Chill / Neo-Soul Loop / Trap Drop / Drill Dark / Latin House / Phonk Vamp / Trap Melodic. With 4-bar and 2-bar cyclic patterns, you have a quick foundation for track-making.
[Grooves] Two new grooves:
- Amapiano: a South African house style featuring a melodic "Log Drum" bassline, laid-back Rhodes chords, and fast 16th-note shakers. Its 4-bar loop is a perfect foundation for your tracks.
- Lo-Fi: a relaxed Lo-Fi hip-hop groove with warm sub bass and a dusty swing. Start a chill beat right away.
We've also consolidated some existing categories: "Blues" and "R&B / Soul" are now combined as "Blues & R&B", and "Acoustic" and "Ballad" are now combined as "Acoustic". All preset content remains fully available.
We've also improved how presets are inserted into split bars. When you add a preset to a bar split into beats (4 or 2), the chords are now distributed to match that bar's split count.
The 7 presets and the Lo-Fi groove are free. Amapiano is a Pro groove, but you can also preview it by watching an ad. If you want to take it further in a DAW, Audio / MIDI export is available with Pro.
Plus various minor improvements and bug fixes, including display stability.
Feedback: support@ototheory.com
2.15.0 May 28
Two new Pro grooves "Nu-Disco" and "Indie Rock" are now available.
"Nu-Disco" delivers modern 2020s disco-pop. With funky 16th-note guitar comping, syncopated synth bass, four-on-the-floor kick, and open hi-hats on the off-beats, you can instantly try trendy dance-pop progressions. Recommended BPM 110-125.
"Indie Rock" delivers 2000s post-punk revival sound. Twin clean guitars with bell-like sparkles create chamber-style indie rock, while driving 16th-note hi-hat ghosts and octave-jumping bass anticipation push forward momentum. Recommended BPM 130-150.
Perfect for producers who want to take it into a DAW. Export to Audio / MIDI ready.
Try any Pro groove for 10 minutes free. Tap a Pro groove and watch a single ad to unlock 10 minutes of full playback. Love it? Subscribe to Pro to keep it unlocked permanently.
Get notified when new grooves are added. We'll send a brief notification whenever a new groove joins OtoTheory. Opt in from the dialog after your first try — turn it off anytime in Settings.
[7-day free trial] Cancel anytime with one tap.
Feedback: support@ototheory.com
2.14.0 May 27
Two new Pro grooves are now available.
"Bossa Nova" delivers authentic Brazilian jazz with six instruments: Nylon Guitar, Acoustic Bass, Drop 2 voicing Piano, Vibraphone, Tenor Sax, and Brazilian Clave Drums.
"Lounge Jazz" recreates modern piano trio jazz with sustained Piano comping, ECM-style Ride cymbal, walking Acoustic Bass, sub-tone Tenor Sax, and feathered Drums.
Both shine as Lo-Fi / Chillhop / Jazz Hop sampling sources. Export to Audio / MIDI and drop them into your DAW. Recommended BPM: Bossa Nova 100-130 / Lounge Jazz 70-115.
[7-day free trial] Cancel anytime with one tap.
Feedback: support@ototheory.com
2.12.0 May 24
[New Pro-only groove: Drop]
Future Bass with deep sub bass + Spread Voicing pad stabs + Saw lead + EP warm layer for bold modern EDM.
[New Pro-only groove: City Pop]
70s-80s urban funk-pop-jazz fusion (Tatsuro Yamashita / Mariya Takeuchi style). DX7 FM E.Piano + Slap Bass + 16-beat funky cutting + Jupiter-6 Pad.
[New Pro-only groove: Arena Rock]
Anthemic stadium rock (Queen / Bon Jovi / U2 / Foo Fighters). Big Stadium Backbeat + ringing Power Chords + Rock Organ wash + Lead Gtr melodic fills.
[Modern Producer Pack — complete]
Three contrasting Pro grooves (EDM Drop + funky City Pop + anthemic Arena Rock) dramatically expand Pro's musical range. 7-day free trial available.
Feedback: support@ototheory.com
2.11.0 May 21
v2.10.0 — Per-Beat Chord Placement + Export & UX Upgrades
[Split bars into up to 4 segments]
Place chords per beat, not just per bar. Long-press, split, then assign a different chord to each beat.
[Grooves sound musical at 4-split]
Bass octave-leap avoidance and leading-tone diatonic constraint. All 22 grooves verified for natural playback.
[PDF Export major upgrade]
Choose 2 to 8 bars per row. Toggle Roman numeral degrees on or off, chord names auto-center, and 4-split overlap is resolved.
[No data loss on time signature change]
4-split chords compressed when switching to 6/8 are fully restored when switching back.
[Pro screen + UX polish]
Pro upgrade screen logo redesigned for Light and Dark modes. Save-confirmation timing improved.
Feedback: support@ototheory.com
2.10.0 May 20
- New "Piano 2" groove (piano + bass + drums) — great for ballad/pop demos.
- "Piano" renamed to "Piano 1" (no drums). Pick the feel that suits your song.
- "Acoustic Guitar" added to Preview Instrument.
2.9.4 May 17
v2.9.3 — Usability & Stability Improvements
- You can now choose your chord preview instrument (Guitar or Piano) in Settings > Preview Instrument.
- Redesigned Pro upgrade screen
The 7-day free trial flow and cancellation steps are now clear at a glance.
- Improved new sketch behavior
When you create a new sketch, the key now properly resets to C Major.
- Better display stability
Fixed a layout issue when returning from the fullscreen fretboard view.
- UI refinements
Cleaned up the Lens view and other tabs.
- Coming next in v2.10: per-beat chord placement.
2.9.3 May 15
v2.9.2 — Minor Refinements
【Improvements】
• Clearer wording for the export confirmation toast
• Improved tap responsiveness of certain menu buttons
Other internal improvements for a smoother experience.
Feedback welcome at support@ototheory.com
2.9.2 May 9
v2.9.1 — Trial & Peace of Mind
【See Your Trial Status at a Glance】
• Trial days-remaining now always shown in Settings
• Friendly reminder when only 1-2 days are left — never miss the deadline
• 24-hour offline grace period keeps Pro features working
even in airplane mode
• Family Sharing entitlements correctly reflected as Pro
2.9.1 May 7
v2.9.0 — Major Build Screen Redesign
■ New & Improved
- Redesigned Build screen built around the editor as the home view
- Color-coded, bold tabs (Suggest / Pick / Instrument / Analyze / AI) for at-a-glance navigation
- Tap any chord in Overview to jump straight to that bar in Build
- Unified capo shape notation across all views (e.g., Key of G with Capo 2 displays F-shape chords)
- Wider chord slots so long names like Cmaj7 and Am7(b5) are no longer truncated
- Save and all exports (Audio, MIDI, PDF, Share) are now accessible from the Mixer
- Audio export progress indicator with phase display and cancel
- Overview auto-scroll pauses for 10 seconds after manual scroll, then resumes
- Redesigned section editing makes it easier to reorder, rename, and manage sections
- Larger modals on iPad (Overview, PDF Preview) with cells, fonts, and legends scaled up
- Simplified splash screen
2.9.0 May 2
This update fixes several issues in our internal analytics tracking. These improvements help us continue refining the user experience. Thank you for your continued support!
2.8.4 Apr 29
【What's New in v2.8.3】
• Save MIDI / PDF directly to the Files app
• New confirmation toast shows where your file was saved
• Audio export still supports AirDrop and share sheet
• Fixed iPad share sheet display issue
• Protects your daily reward when export fails on Free
2.8.3 Apr 27
Bug Fixes:
- Fixed an issue where 6/8 and 12/8 time signatures were not correctly applied when importing songs via AI.
- Fixed a groove/time-signature mismatch that caused incorrect playback after import.
2.8.2 Apr 23
Learn each progression's name and mood, right while you build
■ Presets Rebuilt on Music Theory (56 total)
Every preset now uses its proper music-theory name — Canon Progression, Axis Progression, Plagal Cascade, Andalusian Cadence, Marusa, Komuro, Aeolian Shuttle, and more. Each preset shows Label / Vibe / Description so you can pick the right progression for your mood in seconds.
■ Pattern Detection Expanded from 16 to 56 (Pro)
Pro's Analyze mode now matches your progression against 3.5× more famous patterns. That random chord loop you liked? Turns out it was the Axis Progression all along — and now OtoTheory tells you.
■ Tap Any Pattern to Learn Instantly (Pro)
Tap a detected pattern arrow or list row to see its name, mood, and description in a rich popup. Analysis becomes learning — the way OtoTheory was meant to be used.
2.8.1 Apr 22
6/8 and 12/8 time signatures are here — explore new genres!
■ New Time Signatures
Create in 6/8 and 12/8. Ballads, slow blues, shuffle rock, and more styles you couldn't build before are now at your fingertips.
■ 6 New Grooves
- Ballad (6/8 & 12/8): R&B / soul chord feel
- Arpeggio (6/8 & 12/8): Folk / acoustic fingerpicking
- Rock (6/8 & 12/8): Heavy rock ballad / shuffle rock feel
■ Smooth DAW Integration
MIDI and PDF exports correctly embed 6/8 and 12/8 time signatures, so you can continue your work seamlessly in GarageBand or Logic.
2.8.0 Apr 22
Analyze the chord progressions you create!
■ Chord Progression Analysis (New)
See your progression through a music-theory lens.
- The song's backbone (stability, tension, resolution) shown in color
- The reasons behind "this is the moment that hits" visualized with arrows and labels
- Classic patterns and stylish touches found for you automatically
- Works for analyzing existing songs, too.
■ Easier AI Import
A step-by-step guided flow makes importing chord progressions effortless, even for first-time users.
■ No more jargon walls
Tap the "i" next to any term for both a feel-based description and the theory behind it.
2.7.0 Apr 17
Smarter Chord Suggestions
- The AI tab now shows three clear sections — substitute chords, borrowed chords, and forward push — so you can instantly see *why* each suggestion works. Learn music theory as you create.
- iPad: Transpose & Capo buttons added below fretboard
- Bug Fixes: Various bug fixes and improvements.
2.6.1 Apr 12
- Bug Fixes: Various bug fixes and improvements.
2.5.1 Apr 11
- New Lens feature
See your chord progression from a different perspective, with theory-based suggestions. Explore how it would sound in another key or scale, explained through three layers: Feel, Theory, and Try.
- General improvements
Improved overall app stability and experience.
If you enjoy OtoTheory, a review would mean a lot!
2.5.0 Apr 9
- General improvements
Improved overall app stability and experience.
If you enjoy OtoTheory, a review would mean a lot!
2.4.1 Apr 8
This update includes bug fixes and improvements to enhance your experience.
more Version 2.20.2 1d ago
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