NEXUS lets any LLM into a live multiplayer session over MCP. That is the bold half. The other half is that a language model still cannot reason reliably about harmony. This note is the loop we can run today, and the write we have not finished.
Step through the integration. The tool calls are real and the outputs are the engine's documented answers — this is the exact loop NEXUS + thiri-mcp makes possible, and the build we're bringing to the Audiotool challenge.
Each starts from something the platform already shipped — MCP, community chord tools, a multiplayer session — and pairs it with what we measured or built. This is a research thread, not a partner deck.
NEXUS gives third parties reach into "virtually every part of Audiotool" — free, no license fees, with Splice and Ujam already inside. An open platform earns its bet through the partners who show up early with something real.
A THIRI chord device for the session. A harmony panel any collaborator can use — progressions, voicings, reharmonization — writing chord-skeleton MIDI into the project through @audiotool/nexus, in real time, for everyone in the room.
STATUS — chord device is the remaining write into the session.
The NEXUS showcase leads with a community-built Harmony Editor — clear demand for chord tools, proven by your own builders. Demand like that deserves an engine underneath it.
The production-grade version of that idea. Deterministic analysis, instrument-ready voicings, voice-leading scores, eight reharmonization techniques — an API the whole ecosystem's chord tools can stand on, so community builders get depth for free.
STATUS — comparison not yet run. Demand signal is the community Harmony Editor.
Letting creators bring their own LLM into a live session is the boldest AI move any DAW has made. The demo that sells it is the one where the agent's musical suggestions are actually correct.
thiri-mcp — chord-correct reasoning for every agent that enters. Hosted, live today, already on npm and in Claude and Cursor workflows. Wire an agent to thiri-mcp and a NEXUS session and you have the flagship demo of your own platform story.
STATUS — live today through step 2. Point any agent at mcp.thiri.ai.
"Google Docs meets a creative sandbox" — plus the esports partnerships — says it plainly: your next million users arrive expecting play, not prerequisites. Theory is the wall they hit first.
Harmony as guidance, not homework. In-session rails — suggest the next chord, stay-in-key hints, one-tap reharmonize — powered by the same engine behind Run The Changes, our shipped practice game that turns chord charts into levels. We've gamified theory before; it works.
STATUS — guidance pattern proven in Run the Changes; session prototype open.
The Music Technology Hackathon Montreal (August 22–23, 2026) was the first public write of this thread — a chord device on NEXUS, demoed in person.
An Audiotool-challenge entry, in person. The THIRI chord device was the core of the Montreal write (August 22–23, 2026) — built on NEXUS and demoed live. The remaining work is landing a full band from a chat prompt as tracks in the session.
CONTEXT — Music Technology Hackathon Montreal, August 22–23, 2026.
The SDK is young and moving fast — which is when device APIs for music-intelligence tools get designed. We build against moving APIs and write the findings as we go.
A live stress test of document edit, sync, and MCP. The MCP ecosystem moves monthly. The chord device is how we find where NEXUS document editing and session write still break — findings shared as we go.
STATUS — findings shared as the APIs move. Write Dennison if you are on that stack.
THIRI computes chords, voicings, voice-leading, and reharmonization from pitch-class-set theory — the same answer every time, in milliseconds, from a production API. It ships in the exact shapes NEXUS speaks: an MCP server for agents, a REST API for devices, and an n8n node for workflows.
thiri-mcp is live. The remaining work is landing the changes in the session. If you are building agent surfaces for a DAW, the MCP call is public.
dennison@bluesprincemedia.com · MCP at mcp.thiri.ai · MUTEK Forum, August 22–23, 2026