Measuring Mozart: A Pilot Study Testing the Accuracy of Objective Methods for Matching a Song to a Singer

[Associate Editor's note: In the September 2008 edition of "Voice Research and Technology," I introduced a topic called "Quantifying Tessitura in a Song. " It was more of a teaser than a complete work. My good friend John Nix completed a real study, including dosimetry on a singer who performed a Mozart composition (different from "Il mio tesoro intanto," which I used for my test case)-Ingo R. Titze. ]INTRODUCTIONSelecting appropriate repertoire is a primary responsibility for a singing teacher. Astute repertoire selection can help address the technical and musical development of a singer, as well as advance a singer's career in the case of those who are working professionals. Traditionally, repertoire is assigned on an individual basis by carefully considering the singer's age, gender, technical challenges, personality, musicianship, and developmental level, then cross referencing that singer assessment with an evaluation of the vocal, musical, linguistic, and expressive challenges of potential repertoire.1 A number of print2 and web3 resources exist to assist teachers in choosing potential new literature.In the past, the selection process has depended upon the acquired ability of the singing teacher both to evaluate his or her students and to make judgments about vocal repertoire based upon personal knowledge and close examination of the literature. In recent years, however, the voice range profile (VRP) and voice dosimetry have begun to show promise as objective tools that could assist teachers with the selection process.Several articles have suggested ways in which the VRP could be used or improved upon for determining the voice classification of performers or for guiding repertoire choices. Emerich, Titze, Svec, Popolo, and Logan compared laboratory VRPs for eight professional actors with speech range profiles of the actors during a dramatic scene recorded in a laboratory and on stage in performance.4 At times, the actors exceeded their VRP thresholds when in either of the performance conditions. The study highlighted both the utility of the VRP when comparing laboratory values with actual performance voice usage and the shortcomings of the VRP in predicting what repertoire might exceed a performer's capabilities given the emotional content of live performance. Lamarche, Ternstrom, and Hertegârd also looked at the VRP as compared to the performance of repertoire, combining a commercial VRP program with a response button that subjects pressed during moments of difficult production.5 The subjects, all female professionally trained singers, performed three tasks, including the singing of their best aria, using performance-acceptable quality. Subjects also rated how well the button pressings reflected their experiences and usual vocal challenges; this rating included a viewing of a visual graph of the button responses. The investigators' coupling of objective data from the VRP tasks with (a) the singer's self-assessment captured mid-task and (b) the postperformance evaluation of the data and the responses shows significant promise as a means for enhancing singing teachers' guidance of their students. Lamarche, Ternstrom, and Pabon continued testing improvements of the VRP for singers by examining whether VRPs for singers should be limited to physiological measures (without considering performance quality elements), or whether performance abilities should also be measured in some fashion.6 After testing thirty female subjects, all professionally active singers, they concluded that examining the voice as it is used in performance has clinical importance, and that both types of VRPs should be used for assessing singers. Finally, Herbst, Duus, Jers, and Svec compared the maximum phonation frequency range (MPFR) of amateur choir singers (as gathered during a VRP) with the required pitch range (RPR) for their chosen voice part within a choir, based upon part ranges specified in a commonly used music reference. …