Source-Vocal Tract Interaction in Female Operatic Singing and Theater Belting

(ProQuest: . denotes formulae omitted.) INTRODUCTION HIGH PITCHED SINGING SEEMS to follow two techniques that are clearly differentiated by the operatic style and the music theater style. Both styles (and hence the techniques) grew out of the need to produce intense unamplified vocal sound to large audiences and over considerable large background instrumental accompaniments. The styles have been cultivated over time, even though amplification is now part of some performances in both styles. Several authors have described differences between operatic productions and music theater productions. Sundberg, Gramming, and LoVetri studied a female singer who could produce both styles and concluded that theater belting is characterized by a higher subglottal pressure, by a higher degree of glottal adduction, and a higher larynx position with a concomitant higher first formant frequency on comparable vowels.1 Schutte and Miller pointed out that the second harmonic was characteristically strong in belting and went on record to suggest that, acoustically, the strength of the second harmonic was the defining element of belting.2 Bestebreustje and Schutte studied the strengthening of individual harmonics by formants on several vowels produced in the belt style.3 Vowels with considerable mouth opening, such as / a /and . , needed less modification than the vowels with less mouth opening, like / i / and / u /, to reinforce several harmonics with formants. Stone et al. confirmed several of the conclusions reached by Sundberg et al., namely that belting had a higher subglottal pressure, a stronger second harmonic, a longer glottal closure phase, higher overall formant frequencies, and a long term average spectrum that was skewed to higher frequency partials (all in comparison to the operatic style). 4 The amount of vocal fold adduction (pressedness) used by singers in different styles was studied by Sundberg et al.5 The classical style had the least amount of pressedness, followed by pop, jazz, and blues. Bjorkner included a critical measurement in her comparison of music theater style and opera style.6 For the same lung pressure, music theater production had a greater maximum flow declination rate (MFDR) than opera production. This begins to address source-vocal tract interaction, because MFDR is highly dependent on skewing of the glottal flow pulse, which is produced by vocal tract inertance.7 Titze and Worley described source-vocal tract interaction in male singing at high pitches in the above mentioned styles of production, operatic versus jazz or theater belt.8 The two styles were differentiated acoustically mainly by the way the second harmonic was reinforced by vocal tract inertance. For belt production, the first formant frequency of the vocal tract (F1) was kept above the second harmonic of the source (2F0) by a high larynx position and extreme mouth opening, whereas in operatic production the first formant was lowered by pharyngeal throat widening, larynx lowering, and lesser mouth opening to allow the second harmonic to be well above the first formant. The corresponding supraglottal vocal tracts for these formant-harmonic interactions were identified as a megaphone mouth shape for belt and an inverted megaphone mouth shape for operatic production in a comparable frequency range (around A^sub 4^). It was also pointed out that, historically, a revolution took place around 1830 in male operatic singing. The French tenor Gilbert Duprez introduced a high C (C^sub 5^ = 523 Hz) in chest voice on the opera stage, which some critics thought was anything but appealing.9 It was loud and had a raw quality. In the bel canto era of Rossini, Bellini, and Donizetti (leading up to Duprez's time), tenors sang high notes with a much lighter production. Stark contrasts between so-called chest voice and falsetto voice were avoided in favor of a blended or mixed register production. Later composers such as Verdi, Puccini, and Wagner preferred the robust tenor and baritone sound that contained more of the modal (male speaking) register at high pitches. …