Music Theory and Performance
Music Theory and Performance tests the working knowledge a parish musician uses weekly: modal chant, transposition, vocal ranges, and the intonation habits that keep an ensemble in tune and intelligible.
Reading chant
Chant notation gives four things: the clef (do or fa), the final of the mode, the reciting tone (tenor), and the shape of the formula - intonation, mediation, termination - that makes a psalm tone. The eight modes pair an authentic with a plagal form on each final: 1–2 on D, 3–4 on E, 5–6 on F, 7–8 on G. Mode 8 has final G and tenor C; transposed down a whole step it becomes final F and tenor B♭, and the mode survives because intervallic shape, not absolute pitch, defines it.
Transposing instruments
Rule: written pitch = sounding pitch plus the instrument's transposition. B♭ instruments (trumpet, clarinet) sound a major second lower than written; horn in F sounds a perfect fifth lower; E♭ alto saxophone sounds a major sixth lower. A hymn in E♭ therefore appears in F for a B♭ trumpet, in B♭ for horn, and in C for alto sax.
Intonation and vocal craft
Pure intervals differ from equal temperament: a just major third is roughly 14 cents narrower, a just fifth about 2 cents wider. Unaccompanied choirs that sing thirds by equal-tempered habit drift sharp; ask for a slightly narrowed third and a unified vowel.
Worked example
The alto section goes flat on a sustained "oo" at the end of a motet. Diagnosis: collapsing vowel and shallow support, not a bad ear. Fix: rehearse the passage on "ng" to place resonance, then on "oo" with a hand cue for rib expansion; check whether the sopranos are forcing sharp, which drags the inner voices down. Tune the final chord from the bass upward, adding each voice to the fifth and third. If the passage still fails, transpose down a step.
Traps that cost marks
Confusing written and sounding pitch; forgetting the key-signature change when transposing; missing that tenor parts are often written an octave above sounding pitch; treating "sharp" and "flat" as one problem.