Vibrato extent and intonation in professional Western lyric singing

Two important aspects of singers’ F0 control have been investigated: vibrato extent and intonation. From ten commercially available compact disc recordings of F. Schubert’s Ave Maria, 25 tones were selected for analysis. Fundamental frequency was determined by spectrograph analysis of a high overtone at each turning point of the vibrato undulations. It was found that the mean vibrato extent for individual tones ranged between ±34 and ±123 cent and that the mean across tones and singers amounted to ±71 cent. Informal measurements on Verdi opera arias showed much higher figures. With regard to intonation substantial departures from equally tempered tuning were found for individual tones. A tone’s vibrato extent was found to have a negative correlation with tone duration and a positive correlation with intonation.