terça-feira, 25 de dezembro de 2012

Playing a reed woodwind


6.Playing a reed woodwind

The skill to play an instrument is, as a rule, transmitted from master to apprentice, frequently with the help of "methods" and "études", see Figure 11. These serve as pedagogical complement to the objective study of accomplished works. Sometimes, such as in the cases of the Études for piano by Chopin or for guitar by Villa-Lobos, exercise pieces reach such a high level of musical quality that they become autonomous pieces of music.

In general, the pedagogical material is expected to offer repetitive drills and playing challenges. It is presented to the student in a suitable order and sequence of complexity so as to promote the gradual development of the student's playing technique. Also, students tend to imitate the playing characteristics of their teachers. This is often considered desirable. Very seldom a professional-level classical player is self-taught, while this may occur often in other musical contexts.

In our Western culture, the education in classical music performance belongs to a rather well-established international tradition which, however, allows for some regional/national characteristics. During this process of observation, learning and training, players often develop a strong feeling of identification with musicians with whom they share playing characteristics of their "school". Also, they often have a tendency to reject "schools" representing other stylistic and technical practices.

However the differences in playing technique between different schools seem somewhat exaggerated. A given instrument requires a certain basic behaviour on the part of the player. In addition, the instruments seem to become more and more standardised and a small number of instrument makers dominate the professional market. Also, globalisation in the recording industry and an international job market contribute to reduce the effects of nationality and "schools". As a consequence, the use of professional classical players as subjects in performance experiments tends to be geographically and culturally independent.

Apart from embouchure that has been already mentioned, posture and respiratory movements are regarded as crucial bodily aspects of performance in wind instrument along with the fingering technique. Interestingly, the latter would seem to the layman as the prime factor of playing.

Body posture is part of the performer's visual communication and can be at least partially assessed by the eyes of an experienced instructor, see Figure 11. Respiratory movements, by contrast, are much subtler and often not easy to observe by eye. In addition, posture and respiratory movements are intimately related. For instance, a maximal inhalation often requires changes of posture; a fixed expanded chest posture entails severe exhalatory constraints. A non-invasive respiratory measurement technique, respiratory inductive plethysmography, RIP, was used in Paper IV for objectively monitoring and recording of respiratory movements in performance. It measures variations in cross-sectional area for the estimation of internal thoracic volume changes. Therefore, postural changes that are independent of lung volume variations were expected to generate artefacts. This issue is examined in detail in Paper IV. We believe that this method may be useful for pedagogical and clinical purposes, as it allows monitoring of respiratory movements during musical performance.

Figure 11. Clarinet Lesson. The master usually guides the pupil in every detail of performance, transmitting traditional techniques and esthetical values. The body posture and embouchure shown suggest that the picture was taken at the instant of a quick inhalation. Photo by Blei & Baumann (1987).

A player must resort to many different techniques in realising musical ideas. Some of these techniques, which depart from the traditional ones, are called "extended techniques". In this thesis, some of these techniques have been mentioned and even investigated. One is circular breathing, where the player inhales while maintaining airflow from a reserve volume stored in the mouth cavity. This technique was even used as an experimental task in Paper IIIb. Other extended vocal techniques, such as vocal-ventricular mode phonation, periodic pulse phonation (Strohbass) and growl, are all considered in Paper VI.

Vibrato is a conventional and widespread effect in music. It has been an object of study from different areas, such as music acoustics (Meyer, 1991; Prame, 1994, 1997), music perception and psychology (Seashore, 1932, 1936, 1937, 1938; Brown, 1991), electronic music, and physiology (Gärtner, 1973; Titze, 1994; Hirano et al., 1995).

More effort seems to have been invested into the understanding on how vibrato is generated, than into how it can be practised and taught. Yet, the mechanism generating the vibrato in the wind instruments considered here is far from being exhaustively elucidated. Many musicians and even educators support the idea that vibrato develops "naturally", provided the playing technique is appropriate, and the instrument is "tuned" and properly set. The physical and physiological interpretation of these conditions is however unclear. Against this background it seemed important to examine physiological and aerodynamical aspects of vibrato production. This was carried out in Paper II.


Figure 12. An attempt to a musical parody of the sensorial homunculus representing a player's

somesthetic cerebral cortex in terms of the areas employed during music performance. Adapted from Penfield & Rasmussen (1950).

Playing a wind instrument is often associated with a complex of body movements. It requires a multitude of sensations, particularly those related to hearing, touch in embouchure and fingers, posture, and respiration. In order to illustrate the compatibility of the human tactile potentialities with wind instrument playing, the diagram in Figure 12 is provided, adapted from the classical picture presented by Penfield & Rasmussen (1950). The homunculus figure shows how the extroceptive sensations, i.e. those referring to tactile stimuli, temperature and pain, are represented on the cerebral cortex. The position and extent of the areas of the parietal cortex corresponding to the different parts of the body are mapped. The figure reveals that the lips, tongue and fingers occupy wide areas on the brain surface, particularly as compared with the correlative skin areas. A comparable diagram could be drawn with respect to motor functions, based on the motor homunculus proposed by the same authors.

Apart from the extroceptive sense, proprioception is highly important, being responsible for sensing the excitations in muscles, tendons and joints. This reflects body movement, position and, particularly in wind playing, blowing pressures and aspects of embouchure. In the case of embouchure, extroception and proprioception seem intricately related, since the contraction of the mouth muscles is converted into action on the oscillating reed, which feeds back an intense stimulation of the tactile receptors in the lips. In the case of perception of blowing pressure, however, it can be assumed that the main component is proprioceptive due to the fact that respiratory mechanics involve a great number of muscles, tendons and joints. This is suggested to dominate over the tactile sensitivity of intra-abdominal and trunk parts, as illustrated by the reduced cortical representation in the homunculus, Figure 12. In order to assess the proprioception of blowing pressure in wind players, independently of the other stimuli that usually concur during musical performance, an experiment was devised using a psychophysical production method, Paper V.


      Figure 13. A diagram showing the breathing-related aspects and factors involved in wind instrument playing, and those selected for investigation in this thesis (in bold letters)


Given the multitude of factors involved in wind instrument playing, it was necessary to select those, which were both relevant and feasible to study, see Figure 13.

Blowing pressures were investigated in Papers I and II, where the relationship with pitch, airflow and loudness were considered. From the results it could be assumed that the perception of blowing pressure is a highly relevant factor in wind instrument playing. This assumption was tested in Paper V. Also, there was no detailed information on how those pressures and flow were generated in terms of respiratory movements. This issue was examined in Paper IV. Considerable variations in pulmonary gas, particularly CO2 and O2, can be expected during playing. These variations seemed great enough to affect the instrument's acoustical properties with respect to pitch. The variations and their effects were studied experimentally in Papers IIIa and IIIb. Composer's instructions are normally encoded in a score, representing the typical input to a player. It contains instructions regarding rhythm, dynamical level, pitch, breath pauses and phrasing, all factors considerably affecting the player's breathing and blowing. In our experiments it seemed advisable to use normal-looking scores in describing tasks, since the form of instruction may be relevant to the player's behaviour. The acoustics of the room represents a factor generally considered of major importance to music performance and hence to the players' behaviour. For example, the scaling of dynamic levels (Paper II) and the duration of breathing pauses (Paper IV) can both be expected to vary with this factor. Embouchure is another factor of great significance in wind instrument playing, as explained above. For reasons of limitation, these two last mentioned factors were not studied in depth in this thesis.

It should be borne in mind that the ways of playing reed woodwinds are not exhaustively definable. The instruments are still in their evolution process, in terms of both bore/tonehole design and mechanics, stimulated by a continuous contribution of new research and applied technologies, while still keeping a long-term manufacturing tradition, see Figure 14. New design and materials for the reeds are under continuous development and so is contemporary music, with new requirements and potentialities. Also, the demands on the professional musician are not static. For instance the interaction of mechanical and electronic intruments and multi-instrumentalism, for which the artist must be able to perform on different instruments may be helped by a technology and technique that combines some of the control particularities of different instruments. This development may be furthered by a systematic research in music acoustics and music performance.

      Figure 14. The final rehearsal. Making an instrument requires meticulous craftsmanship and performance tests. Subtle modifications in form and dimension affect the sounding and playing properties. Photo by Blei & Baumann (1987).

      ©1998 by Leonardo Fuks



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