It will come as no surprise that most instrumentalists exhibit a degree of movement during a performance. Through careful analysis of these performances, we are able to form a number of general conclusions.
Firstly, all players who were kind enough to allow themselves to be videotaped displayed a number of ancillary gestures, even though these types of gesture are not necessary to the production of sound. Furthermore, altough unnatural at first, all clarinettists were able to supress most of their expressive movements. This shows that this ability can be learned, and raises questions as to which ancillary gestures have been learned and why.
|Fig.1 A plot of vertical bell movement over time for three performances of Domaines, by P. Boulez. Pierre Dutrieu at the Vrije Universiteit Amsterdam. From top to bottom: Standard performance, exaggerated (expressiveness) and immobilized. Note the supression of movements for the third performance (immobilized).||Fig.2 Similar picture to the one on the left, this time showing the marker on the clarinet mouthpiece and with the third performance zoomed in (immoblized). Check that many movements are still present, although their amplitudes are very small.|
Next, we find that with expert players there exists a strong correlation between their movements at the same points of the score during different performances. This suggests that gestures are by no means randomly produced; rather, they bear a relationship to what is being played and how. For example, a plot of the Optotrak data showing the vertical movement of the clarinet bell is shown on the left, below. On the right is a comparison of two different performances from the same player. Note the similarities in both time and spatial movement over the course of the performance.
|Fig.3 A plot of vertical bell movement over time||Fig.4 A comparison of two bell-movement plots from the same performer - Excerpt of the First Clarinet Sonata, J. Brahms, First Movement.|
Different performers will show overall different patterns, although some of the movements are similar. The next figure shows two performers playing the excerpt of the Brahms sonata (performer #1: red, performer #2: black).
|Fig.5 Several performances of the Brahms first clarinet sonata (excerpt), two different players (red, and black).|
Also, types of common movements can be isolated. One example is the circular movements of the bell in sustained notes.
|Fig.6 Circular movements of the bell, Brahms first clarinet sonata.||Fig.7 Circular movements of the bell, another player.|
Some of the current conclusions of this study are:
- Although expressive movements are an integral part of the performance, clarinettists were able to play without significant movements.
- There seems to be various influences on the resulting expressive movements. These are:
- Material/Physiological, due to respiration, fingering, ergonomics of the instrument.
- Structural, related to the characteristics of the piece, e.g. rhythm, articulation, melodic contour...
- Interpretative, related to the moment of the execution and to each performer's mental model of the piece -- idiosyncratic.
- For the same player playing the same piece, there is a strong correlation between performances at all levels (time, space). Movements are not random, although sometimes changes in strategy are possible.
- For different players playing the same piece, some levels of movements are similar (e.g structural), others idiosyncratic.
Further research will determine whether certain ancillary gestures are common to a certain subset of performer (for instance, students of a particular teacher), or if there exists a relationship to certain musical gestures.