Rebecca B. MacLeod

Perceived Pitch of Violin and Cello Vibrato Tones Among Music Majors

The purpose of this study was to investigate the perceived pitch of string vibrato tones. The authors used recordings of acoustic instruments (cello and violin) to provide both vibrato stimulus tones and the nonvibrato tones that listeners adjusted to match the perceived pitch of the vibrato stimuli. We were interested especially in whether there were differences in pitch perception of vibrato tones between string performers (n = 36) and music majors without string performance experience (n = 36). Both groups of music major listeners perceived the pitch of vibrato tones very near the mean frequency of the vibrato for cello and violin tones. Although means were similar, string players exhibited significantly less deviation in tuning judgments than non-string players for both violin and cello tones. Results appear consistent with earlier perceptual research as well as performance research indicating that string performers vibrate both above and below the intended pitch.

Influences of dynamic level and pitch register on the vibrato rates and widths of violin and viola players

The purpose of this study was to investigate possible influences of pitch register and dynamic level on vibrato rates and widths of university and high school violin and viola players. Analysis showed that pitch register significantly affected the vibrato rates and widths of the performers. Musicians vibrated 0.32 Hz faster and approximately 26 cents wider during high pitches than during low pitches. Dynamic level also significantly affected vibrato width. Performers increased vibrato width approximately 4 cents in the forte passages when compared to the piano passages. Furthermore, violinists demonstrated a tendency to vibrate slightly faster and wider than violists, and university performers varied their vibrato width to a greater extent between the piano and forte passages than did the high school performers. These results, along with further study, can contribute to the development of a systematic method for teaching vibrato.

Initial Movement and Continuity in Vibrato among High School and University String Players

The purpose of the present study was to investigate aspects of vibrato performance among high school and university string players. The main questions were to determine whether students consistently initiate vibrato in an upward or downward direction and whether players vibrate continuously when performing slurs. Forty high school and university violin and cello students played exercises that included tones performed with and without vibrato. We measured direction and magnitude of change when initiating vibrato, pitch levels of vibrated and nonvibrated tones, and duration of nonvibrato when performing slurs. Results showed that these high school and university players did not reveal consistent initial vibrato movements in either direction or magnitude. Performers vibrated both above and below conceived pitch, rather than only upward or only downward. All performers stopped vibrating during the transition between slurred notes. Mean duration of nonvibrato portions of university students (0.42 second) was slightly less than that of high school students (0.50 second). Implications of these results for string pedagogy are discussed. March 28, 2005 June 7, 2005

The effect of articulation style on perception of modulated tempo

We investigated the effect of legato and staccato articulation styles on the perception of modulated tempos. Ninety music majors served as participants. Listeners heard music examples that had been selected from two pieces, each of which included staccato and legato passages. Excerpts were presented to listeners in three conditions of tempo modulation: gradual increases, gradual decreases, or no change. Modulations were produced in small increments so that listeners would not notice any abrupt change in tempo. Results indicated that articulation style and direction of modulation affected listener perception of tempo, and these two factors interacted significantly. All staccato stimuli were judged as increasing in tempo more than legato stimuli; however, differences between the two articulation styles were perceived as larger in tempo-increase examples compared to the no-change and tempo-decrease examples. Implications for performance practice and teaching are discussed.

String Vibrato: Research Related to Performance and Perception

This article presents a summary of our presentation that was invited by the Research Committee of ASTA and given at the 2009 ASTA National Conference in Atlanta. In this article we describe and discuss previous and current research studies concerning string vibrato performance and listeners’ perception of vibrato. Topics addressing performance aspects of vibrato include rates and widths, pitch center, initial direction, and continuity during slurs. Investigations that have used various approaches to determine the perceived pitch center of string vibrato are also summarized. We present suggestions for further investigation of vibrato in both the study of listener perception and performance practice and discuss pedagogical applications of research findings.

Using a Prescreening Rubric for All-State Violin Selection: Influences of Performance and Teaching Experience.

Performance assessment is an integral part of young musicians’ development. Students enrolled in music programs frequently participate in adjudication festivals and many audition for select ensembles. Outcomes of such events are deemed consequential among all concerned: students, parents, teachers, and administrators. Furthermore, the number of all-state applicants for some individual instruments in many states exceeds 100 and in some states approaches or exceeds 200. This is an inordinate number of recordings or live auditions for individuals or judging panels to evaluate. It seems paramount to utilize an efficient yet fair and accurate audition process to assess large numbers of performances in a short period of time. To explore ways of addressing this issue, the authors designed a prescreening rubric with the goal of reducing the number of full-length recordings heard by judges to a more manageable number. The authors then compared ratings of listeners who used the rubric and heard only the étude portion of the audition to scores of trained and experienced judges who heard the entire audition.

Preservice Teachers’ Perceptions of Teaching Effectiveness During Teaching Episodes With Positive and Negative Feedback

The purpose of this study was to examine preservice teachers’ perceptions of teaching effectiveness when viewing teaching episodes with positive and negative feedback. A secondary purpose of the study was to examine several independent variables to determine whether they predicted perceptions of overall teacher effectiveness. Participants watched short teaching clips of eight experienced teachers in an applied teaching setting and rated them for overall teaching effectiveness, subject matter competence, modeling, appropriate feedback, teacher delivery, and teacher demeanor. Teacher videos included four high positive teaching episodes and four high negative teaching episodes and were counterbalanced for gender and instrument (trumpet, piano, voice, and violin). Participants rated positive teachers higher than negative teachers and females higher than males. Teacher delivery was the best predictor of perceptions of teaching effectiveness.

In Tune or Out of Tune: Are Different Instruments and Voice Heard Differently?

We studied music majors’ perception of intonation in accompanied solo performances of trumpet, violin, and voice. We were interested in whether listeners would judge pitch deviations of equal magnitude in the three solo performances as equivalent in intonation. Participants were 150 graduate and undergraduate music majors drawn from two large music schools and included 50 students representing each of the following areas of applied music study: voice, wind instruments, and string instruments. Listeners heard solo trumpet, violin, and soprano performances of Ave Maria (Bach/Gounod) accompanied by piano. Pitch performances of the soloists were altered in four sections of the excerpt and deviated in either the sharp or flat direction within a section by 0, 10, 20, and 30 cents relative to the accompaniment. Listeners judged pitch deviations in the flat direction as more out of tune for the trumpet than equivalent alterations of violin and voice, especially for magnitudes of 20 and 30 cents. In sharp direction changes, violin and trumpet were heard similarly and as more out of tune than the vocal soloist. Additionally, differences in pitch judgments were found between listener groups representing different areas of applied study.

The Influences of Teacher Delivery and Student Progress on Preservice Teachers’ Perceptions of Teaching Effectiveness

The purpose of this study was to examine how teacher delivery and student progress influenced preservice teachers’ perceptions of overall teaching effectiveness. Experienced teachers (n = 6) were videotaped teaching mini applied lessons under four conditions: (a) high teacher delivery and more student progress, (b) high teacher delivery and less student progress, (c) low teacher delivery and more student progress, and (d) low teacher delivery and less student progress. Preservice teachers (n = 75) viewed these teaching excerpts and rated each for teacher delivery, student progress, student musicianship, teacher knowledge of subject matter, and overall teaching effectiveness. Participants rated teachers with high delivery as more effective than teachers with low delivery, irrespective of student progress. There was a moderate positive correlation (r = .53) between perceptions of teacher delivery and student progress. Results of a multiple regression analysis revealed that teacher delivery was the best predictor of perceptions of overall teaching effectiveness, followed closely by student progress.

Perception of melodic intonation in performances with and without vibrato

We compared perception of mistuned intervals in unaccompanied melodies performed by trumpet, violin, and voice, and examined whether there were differences between the three timbres in performances with and without vibrato. Participants were 144 university music students. Listeners heard the three unaccompanied solo performers in two vibrato conditions (with and without vibrato), and three intonation conditions (selected melodic intervals were in tune, sharp 25 cents, or flat 25 cents relative to equal temperament). All three stimuli were perceived as more out of tune when there was no vibrato compared to vibrato. In performances without vibrato, violin was judged as more out of tune than voice and trumpet across all three tuning conditions. Melodies performed with vibrato were judged differently: Violin was judged as least in tune for intervals mistuned in the flat direction, trumpet was heard as least in tune for intervals mistuned sharp, and voice was judged least in tune when intervals were in tune (relative to equal temperament). Differences in perception between timbres may be influenced by characteristics of the vibrato itself such as modulation width, rate, and type.