Flat vs Concentric Rhythm
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Flat
Create, edit, and play sheet music and guitar tabs with this intuitive composer app. It offers a wide range of instruments, notation tools, and collaboration features. Import and export in various formats, and share your creations with a large community.
- Compose and edit sheet music
- Create guitar tabs
- Real-time collaboration
- Import MusicXML, MIDI, PDF
- Export to PDF, MIDI, MP3, WAV
- Large community library
- 90+ instruments
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Write, play and share music, anywhere! Flat is the sheet music app trusted by 5M+ musicians worldwide. Compose, notate, and collaborate on scores for any instrument, from guitar tabs to full orchestras, across iPhone, iPad, Mac, and your web browser. Free features include: → Quick notation input via touch piano, guitar fretboard, or drum pads → 90+ instruments including piano, guitar, violin, saxophone, drums, voice, and more → 100K+ original scores in the community → Edit music scores on iPhone, iPad, Mac, and in your web browser → Hundreds of notation symbols: articulations, dynamics, measures, text, and more → Autocompletion when adding chords → Transposition by key, interval, or tone → Import MusicXML and MIDI files → Import PDF sheet music and convert it into fully editable scores → Keyboard shortcuts for iPad keyboard and fretboard → Share scores publicly or privately Collaborate in real-time: → Real-time collaboration for a dynamic experience → Inline comments for live feedback → Find collaborators in the Flat community Share your music: → Join the monthly Flat community challenge and win prizes → Explore hundreds of thousands of original scores from composers worldwide → Get featured and connect with fellow musicians Subscribe to Flat Power to unlock the full experience across all your devices. Flat Power, premium features: → Unlimited cloud storage → Automatic sync so your full library stays connected on iPhone, iPad, Mac, and web browser → 180+ instruments including high-quality audio → Advanced export: individual parts, multi-rest print, remove Flat branding → Layout and styles: page dimensions, spacing, chord style, Jazz and Handwritten fonts → Custom note heads: Boomwhackers colors, Note Names, Shape-Note (Aiken) → Version history: view and revert to any past version of your scores → Advanced audio: per-part volume and reverb controls → Input notes with MIDI devices (USB and Bluetooth) → Autosave with full version history → Customizable keyboard shortcuts → Priority support → PDF and photo import pages included with every plan: - Monthly plan: 10 PDF import pages/month + full premium features - Yearly plan: 20 PDF import pages/month + full premium features (best value) - Lifetime plan: full premium features + 20 PDF import pages (one-time purchase, no renewal) Terms for in-app payments: Payment will be charged to your Apple ID at confirmation of purchase. The subscription renews automatically unless canceled at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours before the end of the period. Manage and cancel subscriptions in your App Store account settings. Any unused portion of a free trial, if offered, will be forfeited when a subscription is purchased. Our Terms of Service and Privacy Policy: https://flat.io/help/en/policies Questions or feedback: ios@flat.io
Concentric Rhythm
Generate, develop, and explore musical patterns using geometric transformations and simple processes. Visualize musical timelines as circles for intuitive manipulation and create complex rhythms and melodies. Connect to other MIDI-compatible apps and devices.
- Geometric pattern generation
- Circular musical timeline visualization
- Melodic line tools (random-walk, scale-based)
- Rhythmic line generation (cross-rhythms, Euclidean algorithm)
- MIDI output to other apps/devices
- Visualizations of polyrhythms
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Concentric Rhythm is an interactive tool for generating, developing, and exploring musical patterns. It uses geometric transformations and many other simple processes to create, develop, and evolve music. The looping musical timeline is visualized as a circle, which allows you to treat musical patterns as concentric shapes. This makes performing geometric transformations such as rotations, reflections and folding very natural and intuitive. It also provides tools for melodic lines such as random-walk generation and scale-based inversion and transposition. You can generate rhythmic lines using cross-rhythms or the Euclidean algorithm, and allows for great visualisations of complex polyrhythms. Concentric Rhythm now allows you to assign each pattern to a different MIDI channel and send your results to other MIDI compatible apps or devices. Concentric Rhythm was originally developed as a new way to improvise electronic music, but it is also a great tool experimenting with and developing musical material, or just for casually playing with music in a unique, hands-on, way. Many of the ideas here were inspired by the book ‘The Geometry of Musical Rhythm’ and this app is a powerful tool for anyone who is interested in exploring these ideas. But at the same time is easy enough to use that anyone (even with no musical or mathematical background) can make interesting musical patterns and think about the musical world a little differently. Note: There are known compatibility issues when used with AUM, especially on iOS 14
Screenshots
Verdict
The clearest difference is price: Flat at Free against Concentric Rhythm's $3.99. Flat also leads on ratings volume (7K vs 43) and chart position (#139 vs unranked). Concentric Rhythm's advantage is review sentiment (80% vs 68%) and iOS requirement (10.0 vs 16.4). On rating, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Flat is free to download; Concentric Rhythm costs $3.99 up front. Flat sells 10 in-app purchases, starting at $9.99 per month and Concentric Rhythm sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.6 for Flat against 4.7 for Concentric Rhythm. That said, the two scores are not equally well evidenced: Flat has 7K ratings behind it against 43, so its average is the more settled of the two. Written reviews are what separate them: 68% of Flat's written reviews are positive against 80% of Concentric Rhythm's.
Flat ships an update fortnightly, Concentric Rhythm every 2 weeks. The most recent releases landed on November 8, 2026 and November 2, 2026 respectively.
| Parameter | Flat | Concentric Rhythm |
|---|---|---|
| Price | Free — better | $3.99 |
| Rating | 4.6 (7K ratings) | 4.7 (43 ratings) — better |
| Positive reviews | 67.8% of reviews | 80.0% of reviews — better |
| Number of ratings | 7K — better | 43 |
| Update frequency | Fortnightly — better | Every 2 weeks |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | Free with in-app purchases |
| Best chart rank | #139 — better | — |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.4 | 10.0 — better |
| Further details — not scored | ||
| Size | 219 MB | 44 MB |
| Age rating | +4 | 4+ |
| Developer | Tutteo Limited | Jeff Holtzkener |
Customer experience
Flat
Concentric Rhythm
Bugs and requests
Flat
Reported bugs
5 issues- App crashes frequently
- Notes and rests disappear
- Playback issues and audio glitches
- Difficulty selecting and editing notes
- Syncing and saving problems
Requested features
5 requests- Add more percussion instruments
- Improve note entry and editing
- Allow custom soundfonts
- Implement measure repeat signs
- Add more advanced notation options
Concentric Rhythm
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Flat
- Flat Power (Monthly)$9.991 Month
- Flat Power (Yearly)$29.991 Year
- Flat Power (Yearly)$39.991 Year
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- Flat Power (Yearly)$49.991 Year
- PDF import 30 credits$9.99
- PDF import 70 credits$17.99
- Flat Power (Lifetime)$119.00
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- Flat Power (Lifetime)$179.99
- Flat Power (Lifetime)$199.00
- Flat Power (Lifetime)$299.99
Concentric Rhythm
- MIDI Send$4.99









