Choir spacing vs choir formation: Long-term average spectra comparisons

Abstract

Choral methods books have long advised that repositioning choir singers solely according to voice part sung (i.e., choir formation) alters choral sound quality. To date, acoustical studies of choir formation have found no significant mean differences in long-term average spectra (LTAS) attributable to this strategy. Other investigations have indicated that changing the spatial distance between choir singers (i.e., choir spacing) yields significant LTAS differences. As yet, however, no study has compared the LTAS of choir spacing and choir formation conditions using the same choir. This paper reports experiments comparing LTAS of performances acquired from two microphone positions (conductor position, audience position) by three choirs of varied voicing (TTBB, SSAA, and SATB) singing in contrasting inter-singer spacing conditions (close, lateral, circumambient, and uneven) and voice-part formations (block sectional, mixed). Although recording venues and sung literature varied, each of the three choirs exhibited a pattern of significant mean timbral differences according to singer spacing conditions, but not according to formation conditions. Results were discussed in terms of the logics informing the spacing and formation approaches to modifying choir sound and implications for choral practice.