title: Blend in Singing Ensemble Performance: Vibrato Production in a Vocal Quartet.
abstract: OBJECTIVE
  "Blend" is a defining characteristic of good vocal ensemble performance. To achieve this, directors often consider vibrato as a feature to be controlled and consequently restrict its use. Analysis of individual voices in ensemble situations presents several challenges, including the isolation of voices for analysis from recordings. This study considers vibrato production as a feature that contributes to blend through an ecological study of a vocal quartet.
  
  
  METHODS
  A vocal ensemble was recorded using head-worn microphones and electrolaryngograph electrodes to enable fundamental frequency analysis of the individual voices. The same four-part material was recorded over several weeks of rehearsal to allow analysis of conscious and subconscious changes to vibrato production over time. Alongside the recording of their rehearsal discussions, singers were also asked for opinions on vibrato production in connection with blend.
  
  
  CONCLUSIONS
  The results indicate that vibrato is adjusted to some extent by individual singers to improve blend, with some instances of synchrony between voice parts. Some conscious alterations to vibrato were made to improve blend; however, these are not always evident in the data, suggesting that singers' own perceptions of their performance may be influenced by other factors. These findings indicate a need for further studies of vibrato as a feature of blend, particularly in terms of the synergies between expectation and actual production, and potential synchronicity between singers; increased understanding of vibrato in an ensemble setting will lead to more efficient rehearsal techniques and vocal training, and could prevent vocal misuse leading to pathology in the future.
authors.affiliation: Department of Electronics, York Centre for Singing Science, University of York, York, England, United Kingdom. Electronic address: Helena.daffern@york.ac.uk.
authors.forename: Helena
authors.initials: H
authors.lastname: Daffern
mesh_terms: D000162:Acoustics; D004568:Electrodiagnosis; D005260:Female; D006801:Humans; D008297:Male; D012815:Signal Processing, Computer-Assisted; D063346:Singing; D013018:Sound Spectrography; D013997:Time Factors; D014732:Vibration; D014833:Voice Quality; D055815:Young Adult
keywords: Blend; Choral; Ensemble singing; Singing; Vibrato