A conductor must impress on the singers the need for total rhythmic and pitch accuracy; nothing else is satisfactory or musically successful. Artistry and musicality depend on accurate rhythms and pitches.
Some techniques that may improve pitch during a rehearsal are listed below. While these will not solve the problem for the long term they may help immediately and create a better "pitch environment" in which the singer may concentrate.
1. Change the seating arrangement of the choir. A new position in the choir will mean that different voices are heard by each singer. This often creates a good pitch situation and the pitch often improves. The seating arrangement that may get the most dramatic results is the mixed or scrambled arrangement in which no member of the choir is beside another singing the same part. Forming a large circle may also help, or forming each section in a circle, or forming four circles with a mixed arrangement in each circle. This technique may not create lasting proper intonation but they can help the choir sing in tune. The difficulty, as with most techniques, is that the singers must be able to bring the good intonation experience in a different seating arrangement, for example, to the seating arrangement that would be intended for most rehearsals and for the performance.
2. Change the key of the piece (easiest if an a cappella piece), usually by raising the key one-half step. This is often helpful but does not always work. It is not useful if by raising the pitch, the tessitura of one part then becomes a problem.
3. If a choir has rehearsed for some time without an accompaniment, it can be useful to have the accompanist play the parts with the choir
on a piano, or even better, on an organ. A choir can sing out of tune for such a length of time that the singers have no awareness of how the notes or chords are really supposed to sound.
4. If one part is letting the pitch sag have that section sing on "pm" or hum the part while the rest of the choir sings with text. The singers of the part in question can better hear their part in relation to the others.
5. Change style of repertoire. Rehearse a piece of contrasting style, probably one of a faster tempo, requiring fewer longer held notes.
6. Sing the piece in question lightly on "pm", and do the same with text, allowing singers to hear more easily the pitch relationships without any of the vocal problems that may be troublesome.
7. Remember that often pitch problems are simply inaccurate intervals. These can be checked easily using the technique above. An often used technique is to ask the singers to reach higher as they sing higher intervals and "land on the top of the pitch" and do the opposite when singer intervals to lower pitches---minimizing the interval. Hearing the proper internal and then hearing it mentally is critical to singing intervals.
8. One of the best techniques is the reaffirmation of the subdivisions. Utilize the singing of subdivisions as discussed before on the selection in question. Sing part of the phrase and stop. Sing it again and then proceed further each time. On long phrases start at the end and work backward adding one or more notes each time until the entire phrase is sung.
9. Recognize if vocal or physical fatigue is the factor and whether or not the rehearsal should continue. Singers cannot rehearse indefinitely without relief. One should also recognize that some very good rehearsing can take place with the singers singing lightly with or without text.
10. Have the chorus "sing mentally" and then sing aloud at certain chords at your command. The mental pitch the singers carry forward is also the actual pitch they vocalize. Be careful not to overdo this trying to "trick" singers into singing at a wrong time. The point is to carry pitch mentally which encourages the same thing when the choir is singing the actual piece of music.