Pitch drift in a capella choral singing – work in progress

Speak to any choir member or leader about singing music unaccompanied, i.e. a cappella, and they will probably come up with suggestions as to why their choir drifts in pitch at times. The problem doesn’t occur all the time, but it does happen. Extensive literature searches confirm little research has been done on this topic. My research attempts to find out if there are physical reasons why pitch drift occurs and to suggest possible strategies to solve the problem. A review of the literature is presented here. In addition, details of a questionnaire, which is designed to survey choral directors and conductors to try to find possible reasons for the pitch drift problem, are described. The results from the questionnaire, which has recently been disseminated to various societies, will lead to development of appropriate experiments. These experiments will be undertaken with choirs to establish which factors may cause pitch drift and seek possible strategies to help overcome this problem