Objective: Jazz vocalists use a wide range of timbres to express the meaning and emotion of
a song. Collegiate jazz voice instruction teaches vocalists to develop vocal techniques in a
wide array of vocal timbres that allow each vocalist to have multiple timbral options when
expressing a song. This study will compare recordings sung by freshman jazz vocal
performance majors with performances sung by senior and graduate jazz vocal
performance majors by analyzing acoustic data. The purpose of this study is to determine
the effect collegiate jazz voice instruction has on the range of timbres vocalists use while
performing a song.

Methods: 10 subjects (5 freshman, 5 seniors/graduate jazz voice performance majors)
were asked to sing the jazz standard ballad “Misty” in the key of D major in two ways: Mirst
with lyrics and then on the neutral syllable [pae] to serve as a control for vowel. Samples
were then annotated using Praat software to extract all syllables sung on pitches B3
(246.94 Hz), F#4 (369.99 Hz), and B4 (493.88 Hz), and then analyzed for spectrum
centroid and smoothed cepstral peak prominence (CPPS). The data from the freshman
group was then compared with the data from the senior/graduate student group.

Results: Preliminary results show that the sample sets from senior/graduate jazz voice
students yield a wider range of spectrum centroid and CPPS, and thus more timbral
variability, compared to the freshman sample sets. Additionally, the results from the three
matched pitch sets (B3, F#4, and B4) highlight the similarities and differences in timbral
variability in different vocal registers between the freshman and senior/graduate groups.

Conclusions: This study represents one of the Mirst comparisons of jazz vocalists and their
use of timbre. The results reveal that collegiate jazz voice instruction has an effect on the
range of timbres vocalist use while expressing a song. Among the several objectives in
collegiate jazz voice instruction, it includes technical vocal training in many different vocal
qualities and provides students with tools for expression, both of which likely contribute to
the results of this study.