Week 13 — Drill Plan · Two Voices, Heard from Inside

Course: MUS 155 Aural Skills I · Kenosis College
Instructor: Professor Hemsworth
Unit: Learning Unit 13 of 15 (Week 13) · two sessions per week
Objectives: SLO 1 · SLO 2 · SLO 3 · SLO 4
Sessions: session 1 · session 2 (Skills Check 13 in the last quarter hour of session 2; Unit 15's prepared sight-singing set is distributed in session 2)

Instructor-facing. Excluded from the student cartridge. Every stimulus named below is notated, with its performance script, in _keys/KEY-stimulus-sheet-week-13.md; the rounds, the two frames, and the prepared final set are notated in the student P file — nothing musical is spelled out here.

Named in Music Theory I: progression norms; the four motion types; parallel and hidden fifths and octaves; crossing, overlap, and range; tendency tones; writing a second voice against a given line.

First time teaching this

The point of the LU: for twelve weeks the room has heard one line at a time. This week it stands inside a texture of two — singing a round, holding a line against a counter-line, and hearing why the theory rules exist: a second voice is only a second voice while it moves independently. Parallel fifths and octaves aren't "bad"; they're the sound of two voices collapsing into one thickened voice. That's an ear fact before it's a rule, and today the ear gets there first. Scope stays where the morning put it — harmony vocals, countermelodies, bass lines; counterpoint proper waits for MUS 158.

The one thing that must land: independence, felt from inside. A student who can keep singing their line of the round while the other half of the room sings against them has the whole unit.

The most common way it goes wrong: the round collapses — half the room drifts onto the other half's phrase — and the instinct is to slow down and explain. Don't. Rounds fail from tentativeness, not ignorance: sing louder, walk between the groups, conduct both entries with two hands, and restart at full tempo. Second trap: letting session 2 run long and squeezing the prepared-set distribution. That handoff is the break mitigation; protect its five minutes.

The do ritual

Every key change starts with the ritual — play I–IV–V–I, sing do, the class sings do–mi–sol–mi–do back (minor: do–me–sol–me–do). Defined in full in Unit 1's plan; this week it doubles as the door into every new do the rounds and frames use.

Drill sequence

Session 1 — rounds and motion types; minute markers, stimuli by keys-sheet or P name, tempi, reps, words to say.

Session 2 — tendency tones, outer voices, the handoff, the check.

When they miss it

Escalation path

Drop one layer, never the week: the round falls back to unison singing with one instructor-played counter-line; motion ID falls back to M1 vs M4 only (the extremes — mirror vs lockstep); one-against-one falls back to oblique (class holds do while you play the counter-line — Unit 1's hold-your-do, upgraded); outer-voice dictation falls back to bass alone. Re-establish tonic the same way every time: stop, run the do ritual in the working key, resume. Abandon criterion: a segment still failing after two escalated attempts gets banked — say "your ear has the seed; Unit 14 waters it" — and log it. The named pick-up hook: every Unit 13 element re-enters Unit 14 — the frames return as the plain skeleton in the frame-then-flowers game, outer-voice dictation returns at four bars, and tendency hearing returns inside the suspension lean. Nothing is lost.

Tempo table

Rotation note (P states it to students): solo hearings run inside the one-against-one segments — 6 to 8 students per session hold a line alone against the piano, keeping the standing rotation that reaches every voice about every two and a half weeks at 36; in a small room, everyone, both days. Log who has been heard; Unit 15's hearings assume the ledger is current.