Brian
Ferneyhough: La terre est une homme
If you engrave music professionally, you already know what the problems are.
You know that editing a note in bar 47 can mysteriously reflow bar 12 three pages earlier. You know that extracting parts means checking every accidental, every cue, every page turn — again — because the software doesn't quite keep score and parts in sync. You know that large orchestral scores slow to a crawl, that contemporary notation is treated as an edge case requiring workarounds, and that MusicXML moves music between systems only approximately. You know that working on the same score with another musician means emailing files back and forth and hoping nothing was lost in the merge.
You know that Finale was discontinued in 2024 and that thousands of scores in proprietary formats became, overnight, dependent on software that will never be updated again.
These are not minor inconveniences. They cost working musicians and engravers hours per score, and they have persisted for decades because they originate in architectural decisions made in the 1980s and 1990s that cannot be patched away.
Ooloi is built to eliminate them structurally.
Deterministic Layout
When you edit a note, the layout that changes is the layout that should change. Accidental rendering, measure distribution, and system breaks are computed deterministically from the musical content — the same input produces the same output, every time. There is no heuristic correction pass and no cascading reflow. Adjustments are for taste, not necessity.
Score and Parts as One Structure
Scores and parts are views of a single document. A change made anywhere propagates everywhere. There is no manual part extraction, no file duplication, and no opportunity for drift. The score is the single source of musical truth.
Complex Music Without Special Modes
Orchestral scores, microtonal notation, nested tuplets, cross-staff writing, extended techniques — these are handled by the core system, not by add-ons or simplified alternative paths. Simple music is simple to enter. Complex music does not require workarounds. The Ferneyhough and the lead sheet use the same engine.
Responsive at Scale
The architecture uses all available processor cores and GPU-accelerated rendering. Editing a full orchestral score should feel no different from editing a piano piece. The system is designed so that large scores remain responsive under continuous editing, not just when idle.
Open Formats, Long-Term Access
Ooloi is open-source under MPL 2.0. Its file format is inspectable and documented. MusicXML import and export operate on musical meaning rather than graphical approximation, implemented as a first-class plugin with the explicit goal of preserving what other systems discard. Your work is not locked to a vendor, a subscription, or a business model.
Collaboration
The architecture supports real-time collaborative editing as a structural consequence of how musical data is represented, not as a feature added after the fact. Multiple musicians can work on the same score without conflict, corruption, or reduced functionality.
You know that editing a note in bar 47 can mysteriously reflow bar 12 three pages earlier. You know that extracting parts means checking every accidental, every cue, every page turn — again — because the software doesn't quite keep score and parts in sync. You know that large orchestral scores slow to a crawl, that contemporary notation is treated as an edge case requiring workarounds, and that MusicXML moves music between systems only approximately. You know that working on the same score with another musician means emailing files back and forth and hoping nothing was lost in the merge.
You know that Finale was discontinued in 2024 and that thousands of scores in proprietary formats became, overnight, dependent on software that will never be updated again.
These are not minor inconveniences. They cost working musicians and engravers hours per score, and they have persisted for decades because they originate in architectural decisions made in the 1980s and 1990s that cannot be patched away.
Ooloi is built to eliminate them structurally.
Deterministic Layout
When you edit a note, the layout that changes is the layout that should change. Accidental rendering, measure distribution, and system breaks are computed deterministically from the musical content — the same input produces the same output, every time. There is no heuristic correction pass and no cascading reflow. Adjustments are for taste, not necessity.
Score and Parts as One Structure
Scores and parts are views of a single document. A change made anywhere propagates everywhere. There is no manual part extraction, no file duplication, and no opportunity for drift. The score is the single source of musical truth.
Complex Music Without Special Modes
Orchestral scores, microtonal notation, nested tuplets, cross-staff writing, extended techniques — these are handled by the core system, not by add-ons or simplified alternative paths. Simple music is simple to enter. Complex music does not require workarounds. The Ferneyhough and the lead sheet use the same engine.
Responsive at Scale
The architecture uses all available processor cores and GPU-accelerated rendering. Editing a full orchestral score should feel no different from editing a piano piece. The system is designed so that large scores remain responsive under continuous editing, not just when idle.
Open Formats, Long-Term Access
Ooloi is open-source under MPL 2.0. Its file format is inspectable and documented. MusicXML import and export operate on musical meaning rather than graphical approximation, implemented as a first-class plugin with the explicit goal of preserving what other systems discard. Your work is not locked to a vendor, a subscription, or a business model.
Collaboration
The architecture supports real-time collaborative editing as a structural consequence of how musical data is represented, not as a feature added after the fact. Multiple musicians can work on the same score without conflict, corruption, or reduced functionality.
Guitar tablature: plugin territory
Extending Ooloi
Specialised capabilities — guitar tablature, drum notation, jazz changes, playback engines, analytical and educational tools — are implemented as plugins through a published interface. Any JVM language can be used. The plugin system means that niche or experimental needs can be addressed without waiting for core development or destabilising existing functionality.
Input
Ooloi's input system builds on lessons from Igor Engraver's modal workflow — a fast, keyboard-driven approach to notation entry that reflected how musicians think rather than how software typically works. That input method disappeared from the field for over twenty years. It returns here.
Visual Quality
Ooloi uses SMuFL-compliant fonts (Bravura, Petaluma) and follows the engraving standards documented in Gould and Ross. Notational elements are placed algorithmically but remain manually adjustable. Engraving parameters — fonts, line weights, spacing, curvature — can be customised per house style. The goal is output that a professional engraver would accept without correction.
What Ooloi Does Not Do Yet
Ooloi is under development. No release date has been announced. The claims on this page describe architectural properties that have been designed, documented, and in most cases implemented and tested. They do not describe software you can download today. Follow the blog or the newsletter for current progress.
Specialised capabilities — guitar tablature, drum notation, jazz changes, playback engines, analytical and educational tools — are implemented as plugins through a published interface. Any JVM language can be used. The plugin system means that niche or experimental needs can be addressed without waiting for core development or destabilising existing functionality.
Input
Ooloi's input system builds on lessons from Igor Engraver's modal workflow — a fast, keyboard-driven approach to notation entry that reflected how musicians think rather than how software typically works. That input method disappeared from the field for over twenty years. It returns here.
Visual Quality
Ooloi uses SMuFL-compliant fonts (Bravura, Petaluma) and follows the engraving standards documented in Gould and Ross. Notational elements are placed algorithmically but remain manually adjustable. Engraving parameters — fonts, line weights, spacing, curvature — can be customised per house style. The goal is output that a professional engraver would accept without correction.
What Ooloi Does Not Do Yet
Ooloi is under development. No release date has been announced. The claims on this page describe architectural properties that have been designed, documented, and in most cases implemented and tested. They do not describe software you can download today. Follow the blog or the newsletter for current progress.