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Fig. 5.2
The distribution of
canary phrases, in a
bandwidth/tempo space,
representing the natural
tradeoff between bandwidth
and syllabic tempo.
Red
circles
represent the phrases
used for the experiment. The
artificial top right phrases
optimising the two features in
unrealistic ways were the
most successful
Researchers in animal behaviour have long been interested in the phenomenon of
bird song production and its role in the mating process. In several bird species, male
birds produce songs primarily to attract females. The issue of what makes a bird
song more attractive than others has received particular attention in recent years.
Various results have shown that specific features of songs can account for their pop-
ularity. For instance, great reed warbler females (
Acrocephalus arundinaceus
)ex-
hibit a preference for long songs over short ones in the wild (Bensch and Hasselquist
1991
).
More interestingly, the study by Draganoiu et al. (
2002
) focused on the case
of the domesticated canary (
Serinus canaria
). Male canary songs have a specific
phrase structure. Two features of these phrases were shown to significantly increase
liking: frequency bandwidth and trill rate. However, it was also shown that these two
features are somehow contradictory: similarly to Fitt's law, a tradeoff is observed in
real phrases, due to the specific motor constraints of the birds vocal track.
The breakthrough experiment of Draganoiu et al. (
2002
) consisted of synthe-
sising artificial phrases optimising these two features in an unrealistic way that is
'beyond the limits of vocal production'. The exposition of these artificial phrases
to females birds showed unequivocally that females preferred these phrases to the
natural ones (see Fig.
5.2
). An interesting interpretation for this preference is that
the production of 'difficult' phrases maximising both bandwidth and syllable rate
may be a reliable indicator of male physical or behavioural qualities.
This evolutionary argument emphasises the role of virtuosity in music appreci-
ation. In popular music, virtuosity is explicitly present in specific genres (e.g. so-
called
shredding
in hard-rock, illustrated by guitarists such as Yngwie Malmsteen
or melodic-harmonic virtuosity in bebop), as we show below.
5.1.4 Virtuosos as Creators
In this chapter, we adopt a specific perspective on virtuosity. From the viewpoint
of complexity and computer science, we envisage virtuosos as exceptional
problem
