Investigating Vocal Tract Configurations Across Different Belting Qualities in Female and Male Musical Theater Singers Using Real-Time Dynamic MRI.

Abstract

Objectives/hypothesis: To identify vocal tract configuration patterns in vocally healthy contemporary commercial music (CCM) singers during the production of five industry-typical vocal qualities, including various belting qualities and traditional/legit musical theater singing.

Study design: Prospective, observational study.

Methods: Seven professional musical theater singers (four females, three males) performed arpeggiated patterns using five different vocal qualities: traditional/legit, neutral belt, brassy belt, warm belt, and rock belt. Real-time magnetic resonance imaging captured midsagittal vocal tract configurations. Eight morphological measures were analyzed: lip opening, jaw opening, jaw protrusion, tongue dorsum height, uvula elevation, oropharyngeal opening, laryngeal height, and laryngeal tilt. Linear mixed-effects modeling explored relationships between vocal qualities and anatomical measurements.

Results: Lip opening, jaw opening, oropharyngeal opening, and laryngeal height showed significant differences across vocal qualities. The traditional/legit voice quality demonstrated the smallest lip, jaw, and oropharyngeal openings with the lowest laryngeal position. Rock belt showed the largest lip and jaw openings. Brassy belt and rock belt featured larger oropharyngeal space and higher tongue positions than other qualities, creating a "tube-like" shape rather than the previously suggested megaphone shape. Laryngeal positioning was elevated in all belting styles, but not in traditional/legit. No significant differences were found between male and female participants. Lower pitch tasks were characterized by smaller lip, jaw, and oropharyngeal openings compared with higher pitch tasks.

Conclusion: This pilot study revealed distinct vocal tract configurations for different vocal qualities, particularly between traditional/legit and belting styles. The findings challenge previous assumptions about megaphone-shaped vocal tracts in belting, demonstrating more complex configurations. These results provide a foundation for identifying typical versus atypical vocal tract adjustments in CCM singing, with implications for voice pedagogy and clinical practice.