Comparing Contemporary Commercial and Classical Styles: Emotion Expression in Singing

Abstract

Objective: This study examines the acoustic correlates of the vocal expression of emotions in contemporary commercial music (CCM) and classical styles of singing. This information may be useful in improving the training of interpretation in singing.

Study design: This is an experimental comparative study.

Methods: Eleven female singers with a minimum of 3 years of professional-level singing training in CCM, classical, or both styles participated. They sang the vowel [ɑ:] at three pitches (A₃ 220Hz, E₄ 330Hz, and A₄ 440Hz) expressing anger, sadness, joy, tenderness, and a neutral voice. Vowel samples were analyzed for fundamental frequency (fo) formant frequencies (F1-F5), sound pressure level (SPL), spectral structure (alpha ratio = SPL 1500-5000 Hz-SPL 50-1500 Hz), harmonics-to-noise ratio (HNR), perturbation (jitter, shimmer), onset and offset duration, sustain time, rate and extent of fo variation in vibrato, and rate and extent of amplitude vibrato.

Results: The parameters that were statistically significantly (RM-ANOVA, P ≤ 0.05) related to emotion expression in both genres were SPL, alpha ratio, F1, and HNR. Additionally, for CCM, significance was found in sustain time, jitter, shimmer, F2, and F4. When fo and SPL were set as covariates in the variance analysis, jitter, HNR, and F4 did not show pure dependence on expression. The alpha ratio, F1, F2, shimmer apq5, amplitude vibrato rate, and sustain time of vocalizations had emotion-related variation also independent of fo and SPL in the CCM style, while these parameters were related to fo and SPL in the classical style.

Conclusions: The results differed somewhat for the CCM and classical styles. The alpha ratio showed less variation in the classical style, most likely reflecting the demand for a more stable voice source quality. The alpha ratio, F1, F2, shimmer, amplitude vibrato rate, and the sustain time of the vocalizations were related to fo and SPL control in the classical style. The only common independent sound parameter indicating emotional expression for both styles was SPL. The CCM style offers more freedom for expression-related changes in voice quality.

Keywords: Acoustic analyses; Emotion expression; Singing voice; Song genre; Voice quality.