Tessitura Changes in Music Theatre Repertoire for the Soprano Voice

While the term tessitura is often poorly defined and loosely applied, certain statements about its application to singers and their repertoire may be made. For vocal repertoire, tessitura refers to the prevailing note or range of notes in a vocal line. For singers, it refers to the area in which the voice is most comfortably resonant. The definition most frequently used to capture the concept in relation to both singer and repertoire is the range of pitches where a voice or song “sits”. While attempts have been made to quantify tessitura, most references to this term remain largely subjective. This study attempts to objectively measure tessitura by redefining it as an average pitch. A protocol was developed based on Rastall’s formula for calculating a pitch centre of gravity (PCG), taking into account not just the frequency of pitches, but also their duration. This protocol was used to measure changes in tessitura in soprano music theatre repertoire from the 1920s to the 2000s. Although anecdotally recognised by pedagogues and practitioners, the hypothesis that the tessitura of female music theatre repertoire has lowered over time has never been formally tested, despite the existence of parallel studies on the lowering of speaking fundamental frequency (SFF). The results of our study revealed a statistically significant lowering of tessitura in soprano music theatre repertoire over time. The implications of this, and further possible applications of the methodology, are discussed