Objective
Musical theatre singers are often charged with developing belt, mix, and “legit” styles of voicing. Contemporary pedagogues, however, have begun training singers to produce subcategories of mix, such as “chest-dominant mixing” (Saunders Barton, 2018) or “head/mix” and “chest/mix” (Hoch, 2018). Although the research literature includes examinations of belt singing and the more classically-influenced “legit” style (referred to here as “classical crossover”), mixing and its subcategories have not been thoroughly explored.

Methods / Design
The single subject for this pilot study was a cisgender female who is an active musical theatre performer (Broadway, national tours, regional theatre). The primary task was to sing a five-note major scale on an /a/ vowel, sustaining the top note for five seconds. The subject did so in four different self-prescribed styles—belt, belt-mix, head-mix, and classical crossover—in two different keys: E-flat major (with a top note B-flat4) and E major (with a top note of B4).

From the acoustic recordings of each sustained note, we will apply several analyses using the Praat voice and speech analysis software: The spectral slope of the long-term average spectrum (LTAS), the smoothed cepstral peak prominence (CPPS), Spectral Centroid, and the mean fundamental frequency compared to expected pitch to measure intonation. All results will be compared across pitch and style.

The singer also wore an electroglottograph (EGG) to measure changes in vocal fold contact quotient when switching between vocal styles. Additionally, the subject performed the eight vocal tasks a second time while singing into a Phonatory Aerodynamic System (PAS) to capture changes in mean airflow during phonation.

Finally, to relate acoustic, EGG, and aerodynamic metrics to the singer’s perception of ease, the subject rated her perceived effort on a 100 mm visual analog scale ranging from “zero effort” to “most effort” after the completion of each task.

Results and Conclusions
Acoustic and EGG analyses are ongoing, but preliminary examination of data suggest that perceived effort was highest for belt and lowest for classical crossover.