Weeks 3-4 · rhythm · pitch P50 + timing R120, per-beat
Same note, every beat. Pitch holds. Timing holds.
The rule
pass: 4 of 5 with 7/8 pitch AND 7/8 timing
Two diagnostic panels, one trial. Top: per-beat pitch error (sharp above the line, flat below); emerald ±50¢ band. Bottom: per-beat onset error (early above, late below); emerald ±120 ms band. The classic failure mode is pitch-clean but timing-drifty (beats 2 and 6 land 180–200 ms late) — your motor system can hold a steady pitch while the click drags you out of tempo. Both panels must be 7/8 in-band for the trial to pass.
Hear it first
Two references at 80 bpm. A clean trial: one note re-articulated on each click, pitch steady and timing locked. A drifty trial: same pitch but timing slips later and later as the trial goes on. The contrast trains the ear to hear the timing dimension as separate from the pitch.
What’s happening. Repeated notes look trivial — same pitch every beat — but they expose two independent failure modes that single-note matching and pulse-clap can each hide. Pitch drift happens because your larynx subtly resets between articulations; rhythm drift happens because every onset is a new motor decision that your internal clock can miscalibrate. Untrained singers typically lose one axis or the other on the third or fourth beat. ±50¢ + ±120ms per beat is the standard for “recognizably in tune and on tempo” — both axes are independently gated.
Why 4 count-in, why 8 scored beats, why 80 bpm. The 4-beat count-in primes your internal pulse so the first scored beat isn’t a cold start. Eight scored beats is long enough that fatigue and clock-drift surface (less than 4 and you can brute-force; more than 12 and you start grouping into hyper-meter, which is a different skill). 80bpm is around the median tempo of folk and pop — slow enough that miscoordinations are visible, fast enough that you can’t cheat by resetting between beats.
Why this is the gateway to rhythm-pitch combined tasks. Every downstream lesson that combines pitch and rhythm — four-beat-entry, staccato-in-tempo, melodies-with-click, eventually full songs — assumes you can hold a single pitch on a steady pulse. If pitch and rhythm collapse into each other here (one wobbles when the other locks), every two-axis task downstream wobbles too. This is the rhythm-side counterpart of single-note-match: lock both axes on a trivial pitch and the harder tasks open up.
Session ahead
5 trials at 80 bpm · 4 count-in → 8 scored beats · each beat needs pitch ±50¢ AND onset ±120 ms · pass when both panels are 7/8 clean · 4/5 clean trials promotes.