We measured the postural sway of two trombonists as they each recorded multiple performances of two solo pieces in each of three different expressive styles (normal, expressive, non-expressive). We then measured the postural sway of 29 non-trombonist listeners as they moved their arms and body, “air-conducting” the recorded sound as if to draw out the emotion from the performance (Experiment 1), and of the two trombonists as they played along with the same recorded performances (Experiment 2). In both experiments, the velocity of listeners’ postural sway was more like that of the performer than expected by chance. Listeners entrained more to back-and-forth than to side-to-side sway in Experiment 1 and only to back-and-forth sway in Experiment 2. Entrainment was not due entirely to performer and listener both swaying to the musical pulse in the same way. Listeners in Experiment 1 rated performances as more expressive when they entrained more, suggesting that entrainment enhanced their aesthetic experience of the music. The whole body appears to contribute to unpacking the expressive content of musical communication.

PERFORMANCES BY CONCERT PIANISTS in the Western classical tradition are normally highly prepared, yet must sound fresh and spontaneous. We propose that musicians achieve the necessary spontaneity by strategic management of the variability inherent in any action. Musical gestures that make up the artist's interpretation (e.g., crescendos, ritardandos) are attenuated or exaggerated to different degrees in each performance, while movements critical for technique are less varied.We examined 7 highly polished performances of J.S. Bach's Italian Concerto (Presto) by a concert pianist. There were small but consistent differences between performances in 4 of 9 identified musical gestures, each of which occurred in several locations. In contrast, at points where the pianist reported attending to technique during performance, slower tempi and lower dynamic variability suggested that she controlled execution of planned movements more closely. Increased control at technical difficulties permitted more spontaneous variation in the musical gestures important to her interpretation.

HOW DOES AN EXPERIENCED performer memorize when learning a new piece quickly, in just a few hours of practice? To find out, a concert pianist recorded her practice as she learned Clair de Lune by Claude Debussy. She also provided detailed reports on the formal structure of the piece, the performance cues that she selected to attend to while playing, and other decisions about technique and interpretation. These reports were used to determine what she paid attention to during practice and where she had difficulty with memory retrieval. Retrieval practice was one of the main activities throughout the 4 3/4 hours needed to prepare the piece for performance. The pianist tried to play from memory almost from the start, used the musical structure to organize practice, and worked on performance cues to speed up retrieval from long-term memory. Performers practice memory retrieval, even when practice time is limited.

Experts in many fields approach a new problem by identifying the general principles involved before starting work on details. Do expert musicians similarly begin work on a new piece with the big picture, an artistic image of the piece, in mind? To find out, a concert pianist recorded her practice of the third movement, Presto , of J. S. Bach's Italian Concerto , commenting as she did so about what she was doing. The behavioral record of where playing started, stopped, and slowed down indicated the musical dimensions affecting practice, while the comments indicated the main focus of the pianist's attention. An artistic image for the piece was already evident in the initial sight-read performance, guided work on technique in sessions 1-6, and was transformed into a plan for performance by practice of performance cues in sessions 7-8. Interpretive details were added in sessions 9-10 and remaining problems touched up in session 11-12. Despite its pervasive effects on practice, the pianist's artistic image was mentioned only indirectly in comments about technique in sessions 1-6 and about structure, memory, and interpretation in later sessions.