Effects of Gesture Height on Individual and Ensemble Singing

In this study, I explored possible effects of gesture height, specifically the location of the horizontal plane, on singer performance. Research questions for the study included: 1) Do singers change intonation, vibrato rate, vibrato extent, vibrato duration, and tone quality in response to gesture? 2) What are singer participants' perceptions of the effects of gesture on singing? 3) How do expert listeners rate individual and group performances in response to high and low gesture heights? Four stimulus videos were created that featured a conductor directing two verses of My Country, Tis of Thee. Two of the videos incorporated a high conducting plane, with the ictus between the clavicle and the chin of the conductor. The other two used a low conducting plane, with the ictus between the navel and the bottom of the rib cage. For each conducting height condition, the video included instructions for the participants to sing the excerpt on [di] or [dɔ]. Conductor facial expressions and cues were consistent between videos. Participants (N = 48) sang the musical excerpt in all 4 conditions, in a counterbalanced order. Participants were all at least 18 years of age, majoring in music, with voice lesson and choir participation history. Participants were recruited from intact choirs in the College of Music, and signed-up for appointments in groups of 8, two singers per part, SATB. Participants were fitted with a head-mounted microphone apparatus and placed in a semi-circle facing the video screen. Both individual and group audio recordings captured performances in response to all video conditions. Participants completed a post-participation questionnaire regarding their perceptions of gesture in a general sense and in the specific task of this study. From the group performances, recordings were chosen via LTAS plots for analysis by a panel of expert listeners (N = 11). The listeners rated two group recordings; one group evidenced similar responses to the two gestural conditions (according to the LTAS plots), and one group demonstrated different responses to the gestural conditions. Four individual recordings were also rated: (a) a female performance exhibiting similar responses to gesture according to intonation and spectral center of gravity measures, (b) a female performance exhibiting different responses, (c) a male performance exhibiting similar responses, and (d) a male performance exhibiting different responses. Acoustic analysis of individual performances revealed that singers sang slightly less flat in the high condition than the low condition, although there was an interaction with order: Participants sang less flat in response to the second gesture height they saw. No significant differences were seen in measures of vibrato rate or duration between gesture heights. Another order effect was evident in vibrato extent: singers reduced their vibrato extent in the second condition, but by a greater magnitude in the high-low order than the low-high order. No significant differences occurred in tone quality (spectral center of gravity) measures between gesture conditions. Singers' perceptions of the effects of conductor gesture revealed that participants believe that gesture does affect singing, with dynamics, tone quality, and breath being the most frequently cited responses. The expert listener panel did not discriminate tone quality differences between gestural conditions of group performances or the individual female responses. Across the comparisons of male individual recordings, the expert panel rated the low gesture condition significantly higher in tone quality. The present study neither corroborates nor contradicts pedagogical assertions of the effect of gesture on intonation and tone quality. The subjective nature of tone quality, and the difficulty inherent in its quantification, warrants further research. Implications and ideas for future study are discussed.