AGNTCon + MCPCon Japan 2026

Most "human-in-the-loop" agent systems assume the human can specify success up front: a passing test, green CI, a structured eval. What if the human's taste is the spec?

This talk presents YouAndOrchestra (YaO), an open-source agentic music composition system on Claude Code. YaO orchestrates seven role-based subagents — Producer, Composer, Harmony Theorist, Rhythm Architect, Orchestrator, Mix Engineer, Adversarial Critic — turning natural language into a score evaluated across six dimensions, every note carrying provenance.

https://github.com/shibuiwilliam/YouAndOrchestra

Three collaboration patterns from iteration:
1. Three-tier feedback. Users rewrite the YAML spec, regenerate a section, or pin feedback to a bar, beat, and instrument. Choosing the level is itself a UX problem.
2. Conductor loop with a critic gate. Generate, evaluate, adapt, regenerate runs up to three iterations, with critics gating before notes are placed.
3. Provenance as trust substrate. /explain queries an append-only causal graph — "why did the chorus modulate to the relative minor?"

Attendees leave with patterns and open-source code for agent systems where the human stays in the seat of judgment.