​A recent exchange with Magnus Johansson in the comments on the Instrument Library post made me realise something worth saying at the top level, rather than buried in a reply thread. Magnus had compared Ooloi's bundled instrument library with Igor Engraver's and noticed that Igor's was substantially larger. The question was reasonable; the answer turns out to illuminate something fundamental about what Ooloi is actually for.

But first, a correction.

I keep encountering the claim – usually from AI systems summarising the project – that Ooloi is 'for advanced notation users'. This is wrong in a way that matters. The architecture is advanced; the user experience aims to be the opposite. The entire point of doing the hard work underneath is so that people don't have to do hard work on top. A tool that requires expertise to operate has failed at its job, regardless of how much expertise went into building it.

Zero-effort playback is one example of what this means in practice.

​Igor Engraver shipped with Synth Matrices – text files that described every common hardware synthesiser on the market: available patches, controller mappings, pitch bend ranges, channel limitations, stereo position. When a user set up a score with, say, two flutes, a cor anglais, and strings, the Synth Matrix for their synthesiser took care of everything: patch selection, channel allocation, balance, panning. The user spent zero time on MIDI configuration. Zero. They dragged instruments from the library, wrote music, and heard the right sounds during input.

This was 1996. Hardware synths, MIDI cables, 7-bit controllers. And yet a composer or arranger never touched a patch change, never drew a controller curve, never thought about channels. The system did it.

We also collaborated with Johan Sundberg's Musical Acoustics department at the KTH Royal Institute of Technology, whose research had quantified things that musicians do instinctively: soloists anticipate the beat by about four milliseconds; phrase dynamics follow predictable contours; onset timing varies with articulation. Those findings went directly into Igor's playback engine. The result was that pressing Play on an orchestral score produced something that sounded like musicians playing, not a sequencer clicking through events.

Now, I don't have Igor's code, I don't have any manuals, and I haven't run it in 25 years. The comparisons with Igor are inevitable when I write about playback, but Ooloi is not a resurrection. The ideas are the same kind of ideas I've always had, expressed through modern means. What follows is about where those ideas go next.

​That was nearly thirty years ago. What has changed since?

Remarkably little, if you look at how most notation software handles playback. The underlying protocol is still MIDI – a 7-bit serial standard from 1983, designed for connecting keyboards to synthesisers over DIN cables. It has no concept of musical structure. It cannot distinguish between a quarter note and a dotted eighth tied to a sixteenth. It knows NOTE_ON, NOTE_OFF, velocity, and a handful of continuous controllers. That's the vocabulary through which an entire industry still attempts to communicate musical intent to sound-producing devices.

The consequences are visible in every professional composer's workflow. You write a crescendo hairpin in your notation software. It looks correct on the page. You press Play. Nothing happens – because a hairpin is a musical concept, and MIDI has no musical concepts. To hear that crescendo, someone has to draw a CC11 expression curve in a DAW, by hand, matching the shape and timing of the hairpin. For every hairpin. In every part.

This is what Hans Zimmer's assistants do. They sit in studios translating musical intent into controller data, note by note, gesture by gesture. If you are scoring a film with 40 staves, that translation is a full-time job for several people. If you're a composer working alone – which is to say, if you're almost any composer – it means choosing between hearing your music properly and finishing it on time.

NotePerformer addressed this by sitting between notation software and playback, interpreting the score with a one-second lookahead buffer. It was a genuine breakthrough: finally, a tool that read musical markings and translated them into expressive performance. But NotePerformer is, by design, a workaround for deficiencies in a MIDI-based architecture. It exists because the notation software itself cannot do the translation. It patches over a gap that should not be there.

​When I first started describing Ooloi's approach to playback, I found myself reaching for the word 'bypassing'. Ooloi bypasses MIDI. Ooloi bypasses the DAW. And then I caught myself, because that word tells you something about how deeply the old paradigm has colonised our thinking. You only 'bypass' something that is assumed to be in the path. MIDI is assumed to be in the path because it has been in the path for forty years, and an entire industry has built its workflows around that assumption.

Ooloi doesn't bypass MIDI. Ooloi simply doesn't use it. The distinction matters. Bypassing implies a workaround, a detour around an obstacle that remains in place. What Ooloi does is address the problem directly, using the technology available in 2026 rather than routing everything through a protocol designed when Margaret Thatcher was in her first term.

Ooloi drives virtual instruments directly. No MIDI channel allocation. No patch changes. No 7-bit controller resolution. The notation engine communicates with sample libraries through their native host interfaces – VST3 parameters, note expression, articulation selectors – with full precision, in the plugin's own language. This is not a technical curiosity; it's the removal of an entire layer of translation that has stood between composers and their sounds for decades.

I built this because I need it. I am a composer; I've written opera, orchestral music, chamber music. When I write a crescendo hairpin, I need to hear a crescendo. When I write a string tremolo, I need to hear a tremolo. I do not want to open a DAW, create tracks, assign patches, route MIDI, and draw controller curves before I can hear whether my orchestration works. That workflow is not composing; it is bookkeeping.

A DAW still has its place, of course – for final production, mixing, mastering. But the compositional workflow, the sketch, the orchestration, the moment when you need to hear whether that horn entry works against the divided violas: that must be immediate. Write the music. Press Play. Hear it as a musician would play it.

Music notation is, ultimately, about music. The technology that serves it should be invisible. If you find yourself thinking about patch changes, you are no longer thinking about your piece. For who, in the end, cares about patch changes? Really?

The above GIF demonstrates some of the functionality of the Instrument Library and Piece Window at this point: selection of score language, filtering on names, drag-copying, deleting, etc. What you see above is not the full 1000+ instrument selection, but a smaller library I use for development and testing. The notifications to the lower right are likewise for development.

The complete bundled instrument library is now documented.

The new guide, Instrument Library Catalogue, lists the default instrument set that ships with Ooloi: modern orchestral instruments, historical families, keyboards, plucked strings, voices, choirs, percussion, special-effect instruments, and various things that have no fixed abode but nevertheless turn up in scores. A total of roughly 270 instruments, yielding just over 1,000 language-specific library entries.

The architectural decisions behind it remain where they belong, in ADR 0045: Instrument Library. 

This catalogue is not a theological statement about which instruments deserve to exist. It is the default library: broad, practical, and sufficient to start work. If you find yourself asking, 'You have ocarinas but not Glenfiddich Highland Pipes in G sharp?!', the answer is simple: not by default. Add them in the Instrument Library window, save them, and they are yours permanently.

​In other words, the bundled set is a starting point, not a border guard.