Transposing the Motet with a Thin Alto Section
The 10:30 a.m. choir has 18 singers: 6 sopranos, 3 altos, 5 tenors, and 4 basses. They are preparing a motet in E-flat major for Sunday. The soprano line divides to a high B-flat, and the alto section has only three singers, one of whom reads well. The cantor's comfortable range is A3 to D5. The organ is tuned to A=442; the rehearsal-room piano is at A=440. The piece alternates a 6/8 section and a 3/4 section. At Wednesday rehearsal the choir rushes the 6/8 and drags the 3/4; the sopranos sing flat on the divisi. A flute player will double the soprano line. The director wants to transpose down a minor third to C major, but the tenor line would then sit low. Sunday's readings suggest a reflective anthem, while the pastor has asked for something uplifting.
1. Recommend a final key and voicing. Show the transposition arithmetic and the range checks that lead to your decision.
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Do not transpose until every vocal extreme is marked. In E-flat, if the soprano divisi tops on B-flat5, down a minor third to C puts it on G5, which is comfortable for most sopranos. But the alto line in E-flat may descend to G3; down a minor third that becomes E3, below the comfortable alto range for a three-person section, and the tenor line drops from, say, B-flat3 to G3, which will sound weak and force the tenors into falsetto or a shout. A whole step down to D-flat gives A-flat5 for the sopranos, F3 for the altos, and A-flat3 for the tenors, a better compromise if the alto floor is truly G3. Check the actual notes before deciding. If the alto section still cannot hold F3, revoice the lowest alto chord or give that note to the tenors; do not transpose into an unusable alto tessitura. Have the flute double the top line at the octave, and reduce the divisi from three parts to two or a solo if the sopranos are flat. Check the cantor's solo, if any, against A3-D5; if the solo lies outside that range, adjust the solo line or choose a different anthem. My recommendation is D-flat, with a written note to the pastor explaining why the original key and the proposed C major both fail.
2. Diagnose the rhythmic instability in the 6/8 and 3/4 sections and give a rehearsal sequence that addresses it.
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The problem is likely that the choir is following bar lines rather than the text and is not changing conducting gear. In 6/8 the pulse is two dotted-quarter beats, each divided into three eighths; in 3/4 it is three quarter beats. The choir rushes the 6/8 because it is treating the eighth notes as even and accenting every beat, and drags the 3/4 because it is not feeling the forward motion of three. Rehearse with count-singing: say the eighth subdivision aloud in 6/8 and the quarter pulse in 3/4, then transfer to neutral syllables. Conduct the 6/8 with a clear two-pattern and an active rebound for the third eighth; conduct the 3/4 with a light three-pattern and a lifted final beat that leads to the next phrase. Mark the text stresses in the score and have the choir speak the text in rhythm before singing. Slow the tempo until the switch is clean, then increase gradually. Record one run and let the choir hear the transition; repeat only the two bars on either side of the meter change. Do not fix this by beating harder, which usually makes the choir louder and later.
3. Resolve the A=442 organ versus A=440 piano and flute issue for rehearsal and Mass. Include the cent difference and a practical tuning plan.
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The difference is 1200 times log2(442/440), about 7.85 cents. That is small but audible when flute, organ, and voices sustain chords, and it can make the choir sing flat against the organ. The piano cannot be retuned quickly, so do not combine piano and organ at 442. Decide which instrument anchors the Mass: if the anthem is with organ, tune the flute to the organ and rehearse with a digital keyboard set to 442; if the anthem is with piano, use piano alone and leave the organ silent. For rehearsal, set the digital keyboard to 442 and use it for pitch; use the 440 piano only for notes and rhythm, not as the final pitch reference. Give the flute a tuning note from the organ before the liturgy and ask the player to check the octave. Warm up the choir on sustained fifths against the 442 reference, and mark any a cappella passage so it does not drift. If the organ is used for the whole Mass and the piano for the anthem, make the switch explicit in the cue sheet; a silent instrument is better than a half-step battle.