This is the question we get most often from choir directors evaluating tools: DomiSol or Flat.io, which one should I use?
Short answer: they solve different problems. Flat.io is a general-purpose web-based notation editor optimized for staff notation, used by composers, students, instrumentalists, and educators worldwide. DomiSol is a niche editor optimized for tonic solfa and jianpu, the notations used by African church choirs, Chinese and Indonesian instrumentalists, and global hymnody traditions, with a workflow built around how those communities actually rehearse (WhatsApp sharing, mobile-first display, no installation).
If you read this post and conclude “Flat.io is better for me”, that’s a totally reasonable answer. Use the right tool for your repertoire. The rest of this post tries to make the trade-offs concrete.
Side-by-side feature comparison
| DomiSol | Flat.io | |
|---|---|---|
| Editing surface | Tonic solfa + jianpu native | Staff notation native |
| Staff notation | Export only (planned, Pro tier) | Full editing |
| Solfa / jianpu | Native editing | Plugin-style support; not the primary workflow |
| Web-based | ✓ | ✓ |
| Installation | None | None |
| Mobile | Works in any browser | iOS + Android apps |
| SATB workflow | One-click harmonize melody → SATB | Manual voice-by-voice entry |
| Sharing | URL link, no account required to view | URL link or embed; viewer needs account for some features |
| Audio playback | Tone.js synth, browser-native | Tone.js synth + sampled instruments |
| Lyrics | Per-note alignment, multi-language | Per-note alignment |
| AI features | Harmonize, transpose, hum-to-score, lyric translation, image-to-score | Limited |
| PDF export | Solfa/jianpu, free | Free tier limited; paid for unlimited |
| Cost | Free during beta, free tier permanent | Free tier (15 scores), paid ~$10/mo |
| Markdown / version control | Score data is JSON, easy to version | Proprietary .flat format |
| Offline | Limited (PWA install) | Limited |
Use-case scoring
Six things choir directors actually do, and how each tool performs.
1. Composing a new hymn from scratch
Flat.io: Open the editor, pick instruments, start placing notes on a staff. Familiar workflow if you read staff. ~10 min to a basic hymn.
DomiSol: Open the editor, type d r m f s l t directly. The notation IS the editing model. ~5 min to a basic hymn for users who read solfa.
Winner: Tied. Use whichever notation you read fluently. The faster tool is the one that matches your reading mode.
2. Arranging an existing tune to SATB
Flat.io: Manual. Enter soprano, then alto, then tenor, then bass, voice by voice. Voice-leading is your responsibility.
DomiSol: AI tab → Auto-harmonize → pick parts (S/A/T/B) → done. Generated arrangement respects voice-leading rules. Lyrics propagate across all four voices automatically.
Winner: DomiSol, by a wide margin. This is one of the things we built specifically because it’s painful in every other tool.
3. Sharing the finished score with the choir
Flat.io: Generate a share link. Recipients can view in browser. Some advanced features (commenting, suggesting edits) require the recipient to have a Flat.io account.
DomiSol: Generate a share link. Recipients view in any browser, no account needed. Designed specifically to be pasteable in WhatsApp/Slack/email and openable on a $100 Android phone over 3G.
Winner: DomiSol if your choir uses WhatsApp groups (which is to say: most choirs in West Africa, East Africa, Latin America, India, and the Caribbean). Flat.io if your choir is centralized on a Western messaging platform and benefits from in-tool commenting.
4. Printing scores for Sunday service
Flat.io: PDF export works on the free tier with watermark / limits; paid tier is unlimited. Engraving quality is professional-grade for staff notation.
DomiSol: PDF export is free, unlimited, works in solfa or jianpu. Print-ready but cosmetically not as polished as Flat.io’s staff output yet.
Winner: Flat.io if you need staff notation PDFs of professional engraving quality. DomiSol if you need solfa/jianpu PDFs (which Flat.io can’t produce natively at the same quality).
5. Transposing a hymn for a different singer or service
Flat.io: Select all → Transpose → pick interval. Notes shift on the staff; key signature updates.
DomiSol: AI tab → Smart transposition → pick new key. Two modes: simple re-key (instant) or smart voice-leading (AI-assisted, keeps singers in range across the new key).
Winner: DomiSol for choir-specific use cases (the smart voice-leading mode is genuinely useful for SATB transposition). Flat.io for general transposition where you don’t need vocal-range awareness.
6. Onboarding a new choir member who doesn’t read music yet
Flat.io: Send them YouTube tutorials on staff notation. Realistic timeline to basic literacy: 6 months.
DomiSol: Send them the tonic solfa primer and the staff-to-solfa guide. Realistic timeline to basic literacy: 1-4 weeks for vocal music.
Winner: DomiSol if the new member is a vocalist (which is to say: nearly everyone joining a choir). Flat.io if they’re an instrumentalist who’ll be reading staff for ensemble work anyway.
Where Flat.io is genuinely better
Three honest situations where Flat.io is the right call:
- You write staff notation regularly. Flat.io is built for staff. DomiSol’s staff notation is export-only (and not yet shipped). If staff is your primary mode, use Flat.io.
- You collaborate on scores with multiple editors. Flat.io’s commenting, suggesting, and version-history tools are mature. DomiSol’s collaboration story is sharing-as-readonly today; multi-editor features are roadmap.
- You publish to the Flat.io community library or use it pedagogically in a classroom that’s already on Flat.io. Network effects matter; switching tools mid-curriculum costs you more than you save.
Where DomiSol is genuinely better
Symmetric honesty:
- You write solfa or jianpu as your primary notation. This is the case for most choir directors in Africa, the Caribbean, Filipino choirs, and Chinese/Taiwanese/Indonesian musicians. Flat.io can do solfa via plugins, but it’s adding solfa to a staff editor; DomiSol IS a solfa editor.
- Your choir runs through WhatsApp/Slack and reads on phones. DomiSol’s URL-share works on any phone, no account, no app install, and the score renders fast over slow cellular. Flat.io works on phones too but expects more device + account setup.
- You want AI to harmonize, transpose with voice-leading, hum-to-score, or translate lyrics across languages. These are DomiSol-specific features built around the choir-director workflow.
- You want it to stay free. DomiSol is free during beta with the commitment to keep solfa/jianpu editing free in the long-term Pro tier. Flat.io has free + paid tiers and limits the free one.
The honest recommendation
Two flowcharts, depending on what you read:
If you read staff notation as your primary musical language: Use Flat.io. DomiSol may not be the right tool for your workflow today. We’re not trying to displace staff editors, we’re filling a gap they don’t address well.
If you read solfa or jianpu as your primary musical language: Use DomiSol. We built it specifically for you and the workflow tradeoffs in your favor are real (SATB harmonize, WhatsApp sharing, free permanent).
If you straddle both worlds: Use both. Many choir directors do. Use Flat.io for staff scores they share with instrumentalists and orchestra leaders; use DomiSol for solfa/jianpu hymn arrangements they share with the choir. Export between the two via MusicXML when needed.
Related reading
- SATB hymn arranging in tonic solfa, voice-leading, ranges, cadences for choir directors
- Convert sheet music to solfa, bring your existing scores into a solfa workflow
- The best tools for writing jianpu, broader survey including MuseScore, LilyPond, and others
Frequently asked questions
- What's the main difference between DomiSol and Flat.io?
- Flat.io is a general-purpose web-based notation editor optimized for staff notation, with global reach and a polished SaaS experience. DomiSol is a niche editor optimized for tonic solfa and jianpu, the notations used by African church choirs, Chinese instrumentalists, and global hymnody, with WhatsApp-friendly sharing and a workflow built around how those communities actually rehearse. If you write staff music, use Flat.io. If you write solfa or jianpu, use DomiSol.
- Is DomiSol free?
- Yes, free during beta. Future Pro tier (instrument samples, staff notation export) is planned but jianpu and solfa editing will stay free.
- Is Flat.io free?
- Flat.io has a free tier that's generous for individuals (up to 15 scores) and a paid plan starting around $10/month for unlimited scores and additional collaboration features. Pricing changes; check flat.io/pricing for the current tiers.
- Can I use both?
- Absolutely, the tools solve different problems. Many choir directors use Flat.io for staff scores they share with instrumentalists and DomiSol for solfa/jianpu hymn arrangements they share with the choir.
- Can I import my Flat.io scores into DomiSol?
- Yes, export your Flat.io score as MusicXML, then import into DomiSol via AI tab → Import file. The conversion preserves notes, key signature, time signature, and tempo. You can then edit in solfa or jianpu and re-share via URL.