Laura Bishop

When they listen and when they watch: Pianists' use of nonverbal audio and visual cues during duet performance

Nonverbal auditory and visual communication helps ensemble musicians predict each other’s intentions and coordinate their actions. When structural characteristics of the music make predicting co-performers’ intentions difficult (e.g., following long pauses or during ritardandi), reliance on incoming auditory and visual signals may change. This study tested whether attention to visual cues during piano–piano and piano–violin duet performance increases in such situations. Pianists performed the secondo part to three duets, synchronizing with recordings of violinists or pianists playing the primo parts. Secondos’ access to incoming audio and visual signals and to their own auditory feedback was manipulated. Synchronization was most successful when primo audio was available, deteriorating when primo audio was removed and only cues from primo visual signals were available. Visual cues were used effectively following long pauses in the music, however, even in the absence of primo audio. Synchronization was unaffected by the removal of secondos’ own auditory feedback. Differences were observed in how successfully piano–piano and piano–violin duos synchronized, but these effects of instrument pairing were not consistent across pieces. Pianists’ success at synchronizing with violinists and other pianists is likely moderated by piece characteristics and individual differences in the clarity of cueing gestures used.

Musical Expertise and the Ability to Imagine Loudness

Most perceived parameters of sound (e.g. pitch, duration, timbre) can also be imagined in the absence of sound. These parameters are imagined more veridically by expert musicians than non-experts. Evidence for whether loudness is imagined, however, is conflicting. In music, the question of whether loudness is imagined is particularly relevant due to its role as a principal parameter of performance expression. This study addressed the hypothesis that the veridicality of imagined loudness improves with increasing musical expertise. Experts, novices and non-musicians imagined short passages of well-known classical music under two counterbalanced conditions: 1) while adjusting a slider to indicate imagined loudness of the music and 2) while tapping out the rhythm to indicate imagined timing. Subtests assessed music listening abilities and working memory span to determine whether these factors, also hypothesised to improve with increasing musical expertise, could account for imagery task performance. Similarity between each participant’s imagined and listening loudness profiles and reference recording intensity profiles was assessed using time series analysis and dynamic time warping. The results suggest a widespread ability to imagine the loudness of familiar music. The veridicality of imagined loudness tended to be greatest for the expert musicians, supporting the predicted relationship between musical expertise and musical imagery ability.

Musical imagery and the planning of dynamics and articulation during performance

Musicians anticipate the effects of their actions during performance. Online musical imagery, or the consciously accessible anticipation of desired effects, may enable expressive performance when auditory feedback is disrupted and help guide performance when it is present. This study tested the hypotheses that imagery 1) can occur concurrently with normal performance, 2) is strongest when auditory feedback is absent but motor feedback is present, and 3) improves with increasing musical expertise. Auditory and motor feedback conditions were manipulated as pianists performed melodies expressively from notation. Dynamic and articulation markings were introduced into the score during performance and pianists indicated verbally whether the markings matched their expressive intentions while continuing to play their own interpretation. Expression was similar under auditory-motor (i.e., normal feedback) and motor-only (i.e., no auditory feedback) performance conditions, and verbal task performance suggested that imagery was stronger when auditory feedback was absent. Verbal task performance also improved with increasing expertise, suggesting a strengthening of online imagery.

Mental Imagery for Musical Changes in Loudness

Musicians imagine music during mental rehearsal, when reading from a score, and while composing. An important characteristic of music is its temporality. Among the parameters that vary through time is sound intensity, perceived as patterns of loudness. Studies of mental imagery for melodies (i.e., pitch and rhythm) show interference from concurrent musical pitch and verbal tasks, but how we represent musical changes in loudness is unclear. Theories suggest that our perceptions of loudness change relate to our perceptions of force or effort, implying a motor representation. An experiment was conducted to investigate the modalities that contribute to imagery for loudness change. Musicians performed a within-subjects loudness change recall task, comprising 48 trials. First, participants heard a musical scale played with varying patterns of loudness, which they were asked to remember. There followed an empty interval of 8 s (nil distractor control), or the presentation of a series of four sine tones, or four visual letters or three conductor gestures, also to be remembered. Participants then saw an unfolding score of the notes of the scale, during which they were to imagine the corresponding scale in their mind while adjusting a slider to indicate the imagined changes in loudness. Finally, participants performed a recognition task of the tone, letter, or gesture sequence. Based on the motor hypothesis, we predicted that observing and remembering conductor gestures would impair loudness change scale recall, while observing and remembering tone or letter string stimuli would not. Results support this prediction, with loudness change recalled less accurately in the gestures condition than in the control condition. An effect of musical training suggests that auditory and motor imagery ability may be closely related to domain expertise.

Beating time: How ensemble musicians’ cueing gestures communicate beat position and tempo

Ensemble musicians typically exchange visual cues to coordinate piece entrances. “Cueing-in” gestures indicate when to begin playing and at what tempo. This study investigated how timing information is encoded in musicians’ cueing-in gestures. Gesture acceleration patterns were expected to indicate beat position, while gesture periodicity, duration, and peak gesture velocity were expected to indicate tempo. Same-instrument ensembles (e.g., piano–piano) were expected to synchronize more successfully than mixed-instrument ensembles (e.g., piano–violin). Duos performed short passages as their head and (for violinists) bowing hand movements were tracked with accelerometers and Kinect sensors. Performers alternated between leader/follower roles; leaders heard a tempo via headphones and cued their partner in nonverbally. Violin duos synchronized more successfully than either piano duos or piano–violin duos, possibly because violinists were more experienced in ensemble playing than pianists. Peak acceleration indicated beat position in leaders’ head-nodding gestures. Gesture duration and periodicity in leaders’ head and bowing hand gestures indicated tempo. The results show that the spatio-temporal characteristics of cueing-in gestures guide beat perception, enabling synchronization with visual gestures that follow a range of spatial trajectories.

Communication for coordination: gesture kinematics and conventionality affect synchronization success in piano duos

Ensemble musicians often exchange visual cues in the form of body gestures (e.g., rhythmic head nods) to help coordinate piece entrances. These cues must communicate beats clearly, especially if the piece requires interperformer synchronization of the first chord. This study aimed to (1) replicate prior findings suggesting that points of peak acceleration in head gestures communicate beat position and (2) identify the kinematic features of head gestures that encourage successful synchronization. It was expected that increased precision of the alignment between leaders’ head gestures and first note onsets, increased gesture smoothness, magnitude, and prototypicality, and increased leader ensemble/conducting experience would improve gesture synchronizability. Audio/MIDI and motion capture recordings were made of piano duos performing short musical passages under assigned leader/follower conditions. The leader of each trial listened to a particular tempo over headphones, then cued their partner in at the given tempo, without speaking. A subset of motion capture recordings were then presented as point-light videos with corresponding audio to a sample of musicians who tapped in synchrony with the beat. Musicians were found to align their first taps with the period of deceleration following acceleration peaks in leaders’ head gestures, suggesting that acceleration patterns communicate beat position. Musicians’ synchronization with leaders’ first onsets improved as cueing gesture smoothness and magnitude increased and prototypicality decreased. Synchronization was also more successful with more experienced leaders’ gestures. These results might be applied to interactive systems using gesture recognition or reproduction for music-making tasks (e.g., intelligent accompaniment systems).

Collaborative Musical Creativity: How Ensembles Coordinate Spontaneity

Music performance is inherently social. Most music is performed in groups, and even soloists are subject to influence from a (real or imagined) audience. It is also inherently creative. Performers are called upon to interpret notated music, improvise new musical material, adapt to unexpected playing conditions, and accommodate technical errors. The focus of this paper is how creativity is distributed across members of a music ensemble as they perform these tasks. Some aspects of ensemble performance have been investigated extensively in recent years as part of the broader literature on joint action (e.g., the processes underlying sensorimotor synchronization). Much of this research has been done under highly controlled conditions, using tasks that generate reliable results, but capture only a small part of ensemble performance as it occurs naturalistically. Still missing from this literature is an explanation of how ensemble musicians perform in conditions that require creative interpretation, improvisation, and/or adaptation: how do they coordinate the production of something new? Current theories of creativity endorse the idea that dynamic interaction between individuals, their actions, and their social and material environments underlies creative performance. This framework is much in line with the embodied music cognition paradigm and the dynamical systems perspective on ensemble coordination. This review begins by situating the concept of collaborative musical creativity in the context of embodiment. Progress that has been made toward identifying the mechanisms that underlie collaborative creativity in music performance is then assessed. The focus is on the possible role of musical imagination in facilitating performer flexibility, and on the forms of communication that are likely to support the coordination of creative musical output. Next, emergence and group flow–constructs that seem to characterize ensemble performance at its peak–are considered, and some of the conditions that may encourage periods of emergence or flow are identified. Finally, it is argued that further research is needed to (1) demystify the constructs of emergence and group flow, clarifying their effects on performer experience and listener response, (2) determine how constrained musical imagination is by perceptual experience and understand peoples capacity to depart from familiar frameworks and imagine new sounds and sound structures, and (3) assess the technological developments that are supposed to facilitate or enhance musical creativity, and determine what effect they have on the processes underlying creative collaboration.