Month: March 2013

The biological basis of orchestra seating

Many cultural conventions appear like the result of historical accidents. The QWERTY – keyboard is a typical example: the technical requirements of early typewriters still determine the computer keyboard that I write this text on, even though by now technical advances would allow for a far more efficient design. Some culturally accepted oddities, however, appear to reflect the biological requirements of human beings. The way musicians are seated in an orchestra is one such case, but the listener is, surprisingly, not the beneficiary.

When one goes to a concert one typically sees a seating somewhat like the one below: strings in the front, then woodwinds further back, then brass. What is less obvious is that, in general, higher pitched instruments are seated on the left and lower pitched instruments on the right. The strings show this pattern perfectly: from left to right one sees violins, violas, cellos and then basses. Choirs show the same pattern: higher voices (soprano and tenor) stand left of the lower voices (alt and basses). Why is that?

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orchestra; seating arrangement; Nijmegen; Nijmegen studenten orkest

An orchestra I have personally performed with.

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It turns out that this is not a historical accident but instead a biological requirement. Diana Deutsch has used a series of audio illusions which all showed a curious pattern: when you present two series of tones each to one ear, you have the illusion that the high tones are being played to your right ear and the low ones to the left ear. In case you don’t believe me, listen to this illustration of Deutsch’s scale illusion:
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Apparently, there is a right ear advantage for high tones. So, seating the higher instruments on the left side (as seen on the photo) makes complete sense as this way musicians on stage tend to hear higher tones coming from their right. However, from the point of view of the audience this is actually a really bad idea as their right ear advantage is not taken into account. It turns out that orchestra seating arrangements are not favouring the hearing of the audience or the conductor but instead the musicians!
The right ear advantage for high tones is even mirrored in musicians’ brains. We know that the right ear projects mostly to the left auditory cortex and vice versa for the left ear. So, one would expect that people who play high instruments have trained their right ear / left auditory cortex the most when they practiced their craft. These training effects should be mirrored in differences in cortex size. This would mean that people sitting on the left in an orchestra have bigger left auditory cortices. In a fascinating article Schneider and colleagues showed that by and large this is the case: professional musicians who play high instruments or instruments with a sharp attack (e.g., percussionists, piano players) tend to have greater left auditory cortices than right auditory cortices. Their figure says is all.
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Schneider; orchestra; seating; brain; Heschl's gyrus; primary auditory cortex; cortical size

How the brains are seated in an orchestra.

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The orchestra seating arrangement mirrors not only the listening biases of most human ears but on top of that the brain differences between musicians. By and large, the orchestra is organised according to biological principles. Thus, not all cultural conventions – like the seemingly arbitrary seating arrangement of orchestras – have their roots in historical accidents. Cultural oddities are sometimes merely down to biology.

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Deutsch, D. (1999). Grouping Mechanisms in Music The Psychology of Music, Second Edition, 299-348 DOI: 10.1016/B978-012213564-4/50010-X

Schneider P, Sluming V, Roberts N, Bleeck S, & Rupp A (2005). Structural, functional, and perceptual differences in Heschl’s gyrus and musical instrument preference. Annals of the New York Academy of Sciences, 1060, 387-94 PMID: 16597790

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Figures:

1) Nederlands: Symfonieorkest Nijmegen in de grote zaal van de Vereeniging, The SON photo library, via wikimedia

2) as found in Schneider et al., 2005, p. 392

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