VR Guitar Tuner

• VR-native spatial tuner — anchored to the guitar via passthrough + hand-tracking, head-locked fallback.
• Real-time pitch DSP (autocorrelation + cents), Rust audio path for low-latency analysis.
• Dual model: standalone app + embeddable SDK for third-party VR music apps.
• 10-document strategy stack (BMC, UX, UI, technical, QA, GTM, branding) — planning depth as deliverable.
• Agent-driven dev workflow: scoped skills + hooks in a structured .agents/ directory.

VR music apps (Paradiddle, Unplugged, Virtuoso, jam-rooms) are great until a string drifts. Then you pause the experience, lift the headset, find your phone or a clip-on tuner, tune, put the headset back on, re-orient, and lose flow. The whole point of immersion is broken by a 30-second hardware errand. No spatial tuner exists for Quest 3 yet — the gap is obvious once you've tried.

A standalone Quest 3 / Vision Pro app, plus an SDK third-party VR music apps can embed. The headset's microphones drive a DSP pitch-detection pipeline (autocorrelation + cents-deviation); a 3D spatial tuning interface anchors to the guitar headstock via passthrough hand-tracking, or floats head-locked if the user prefers. Built in Rust for the audio path (latency-sensitive), Wasm for the cross-platform parts, and the Quest SDK on top.

Pre-development. The deliverable so far is a 10-document strategy stack — BMC + financials, project goal report (W5H, OODA, Pareto), UX (personas, journeys, pre-mortem), UI (mood boards, design system, screen specs), technical architecture, QA strategy, marketing/sales plans, branding, and a master document. The codebase scaffolds an agent-driven dev workflow (Cargo + .agents/ directory of scoped tools per phase). Surfaced here as a strategic R&D case: the planning depth is the work product right now; the binary follows.