Pre-Performance Practices: Breathing Imagery and Warm-Up For Singers

Abstract

Research clarifying whether silent warm-up is possible and what constitutes a warmed-up voice is lacking. The acoustic correlates of a warmed-up voice are not clear, and perceptual correlates have centred on singers’ rather than both singers’ and listeners’ perceptions. This thesis therefore investigates acoustic and perceptual changes following vocal warm-up and breathing imagery, and whether breathing imagery may serve as a silent warm-up for singers. The literature review covers the acoustic and perceptual factors critical to optimal tone quality in singing, and the challenges of vocal assessment. It presents an historical survey of imagery and discusses the role of imagery in singing. It also investigates the relationship between optimal performance and vocal warm-up. As both imagery and warm-up for the voice are lacking thorough investigation, the review is supplemented with findings from sports psychology and sports medicine. In study 1, singers were recorded before and after three non-vocal 25 minute tasks. One task involved imagery of the breath directed upwards and downwards as far from the larynx as possible. Such imagery has played an important role in voice teaching since at least the 16th century. Another 25 minute task used Braille script as employed in the reading of music by the visually impaired. This provided the opportunity for the singer to engage in tactile, kinaesthetic and visual imagery related to music yet unrelated to breath function. A third task was a non-imagery breath-related activity that required the completion of a cloze passage about breath function for singers. In study 2, singers were recorded before and after a 25 minute vocal warm-up. The singers’ vocal signals were acoustically analysed for pre- to post-test changes in vibrato rate, vibrato extent and sound pressure level. Singer-subjects self-assessed their performances, and listener-judges perceptually rated the vocal samples presented in a fully randomised block design. Acoustic results for both breathing imagery and vocal warm-up produced three notable changes in vibrato rate: (i) more regularity in the cyclic undulations comprising the vibrato rate of a note, (ii) more stability in mean vibrato rates from one sustained note to the next, and (iii) a moderating of excessively fast and excessively slow mean vibrato rates for solos. The alternate imagery task based on Braille music code produced slower, less regular vibrato rates. This may have been due to the singers becoming too relaxed, as links are sometimes noted between imagery and relaxation. The non-imagery cloze passage task produced no significant change in vibrato from pre-test to post-test. Singers indicated that they sang better and felt warmed up after both the breathing imagery and vocal warm-up. The majority of listener-judges, however, concurred only in cases where the singer’s pre-test vibrato rate was either the fastest for the group, the slowest for the group or the most unstable for the group. Unlike vibrato rate, vibrato extent showed no consistent patterns of change acoustically as a result of any intervention. This thesis attempts to broaden our understanding of the relationships between imagery, warm-up and vibrato change. The findings support the use of vibrato analysis in the investigation of pedagogical practices. Furthermore, they indicate that change in the quality of vibrato, which impacts on tone quality, is central to both vocal warm-up and the long-standing use of directional imagery by singers. The findings of these studies may have direct bearing on teaching practice, physical and mental preparation, and the quality of vocal performance.