Choirs are not able always to maintain the pitch of the piece of music when they are performing a cappella. That is to say, when the performance requires no instrumental accompaniment or when the accompaniment is removed for musical effect and then, at some time later, reintroduced.
In the case of the former, the drift from the intended pitch may not be so obvious to an audience other than to those with knowledge of, and the ability to recognize, the pitch. In the case of the latter, however, the reintroduction of instrumental accompaniment will make any drift in pitch very obvious. A literature review is ongoing and a survey of choral conductors, animateurs and directors is in hand.
A survey has been designed to ask choral practitioners about their choirs, their rehearsals and for suggestions as to possible reasons for the occurrence of pitch drift.