Weeks 5-6 · range · SOVT glide across a sixth
Glide a sixth up and back on a lip trill. No breaks.
The rule
pass: smooth contour · no break > 250 ms · ≥ 9 semitones
A continuous emerald glide rises from the tonic to about a sixth above, then slides back down. The grey trace below shows the same target with a register break near the top of the climb — that gap, longer than 250 ms, is the failure mode and what most untrained voices hit when they pass through their first passaggio.
Hear it first
Two reference glides. A clean one sounds like a single sliding pitch — no audible jump, no break, no sudden timbre change. A failing one has a click or a vowel-shift halfway up. Listen for continuity.
What’s happening. Most untrained voices have a register transition (the primo passaggio) somewhere in the middle of their range — the spot where chest-dominant phonation hands off to head-dominant. Without coordination, the larynx briefly seizes and you get a click, a yodel, or a complete dropout. The lip trill removes most of the laryngeal load, so your only job is keeping the airflow continuous through that hand-off.
Why a sixth, why 250 ms. A major sixth (9semitones) almost certainly crosses the primo passaggio for most voices — large enough to force the transition, small enough that you don’t hit the secondo passaggio too. A 250 ms break is the threshold at which the gap becomes audible as a discontinuity rather than legato variation. Below that, the ear stitches it back together.
Why this is the bridge.The whole register-event-detection, passaggio-siren, one-octave-scale-fragment chain depends on this gesture being settled on the easiest possible configuration first. If you can’t glide a sixth on a lip trill, you cannot glide an octave on a vowel. Lock the airflow continuity here before adding vowel complexity.
Session ahead
8 trials · lip-trill glide across ≈ 9 semitones · max gap 250 ms · hit 5 to pass.