Weeks 1-2 · body / use · stacked posture with free neck and jaw
Stand stacked. Release the jaw. Hold both for five seconds.
The rule
pass: mean alignment ≥ 85% · neck/jaw ≤ 2/5
Two things must be true at once. The emerald trace up top stays inside the alignment band for the full 5seconds — that’s your head over shoulders, ribs over hips, no drift. Below, the tension scale: a self-rated 0-2 sits in the emerald region (released); anything higher is clenched and fails the release half of the criterion.
Feel it first
Two body checks before the camera scores you. Soft knees, lifted crown — that’s the alignment cue. Drop the jaw with the tongue forward and flat — that’s the release cue. If you can’t do both standing still, you can’t do them singing.
What’s happening. Estill body-use treats an open ribcage and a free jaw/tongue as preconditions for any sustained voicing. Forward head, slumped ribs, or a gripped jaw all transmit tension straight to the larynx. Untrained singers default to one of these even without singing — the camera catches it because alignment drift exceeds about 15% of frame within seconds of standing still.
Why 5 seconds, why a camera.A phrase typically lasts 4-8 seconds. If you can’t hold stacked alignment for 5, you can’t hold it through a phrase. The camera (MediaPipe pose landmarker, on-device only) reads your skeleton at 30 fps so “stand still” becomes a measurable thing instead of a coaching guess.
Why this is the foundation. This is the first lesson because every later one assumes it. Silent-breath-hiss depends on diaphragmatic breathing (only possible with open ribs). Hum-onset depends on an unclenched larynx (only possible with a released jaw). Every sustained tone and every long phrase inherits whatever this lesson leaves untrained.
Session ahead
5 trials · 5s hold each · pass = mean alignment ≥ 85% · hit 4 to advance. Body landmarks run on your device via MediaPipe — no video leaves your browser.