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Fig. 10.6
Mapping diagram for musi
cation of EEG proposed by Wu et al. (
2010
)
brainwave states as he heard them. Alpha waves, or alpha rhythms, are the term
given to describe brain activity within the range of 8 and 13 Hz and are commonly
associated with relaxed states of attentiveness (Cahn and Polich
2006
).
During the performance, Lucier ampli
ed his alpha waves, read from two
electrodes positioned on his forehead, through a series of loudspeakers. As the
frequencies contained in alpha waves are below the threshold of human hearing, the
loudspeakers were coupled with resonant percussive instruments including cym-
bals, gongs, bass drums and timpani as a way of musifying brainwave activity
(Lucier
1976
).
This simple method of directly mapping brainwave intensity to instrument res-
onance was the
first attempt of its kind to interpret brainwave activity in real time
into a form of experimental music. The theatrical dramaturgy of a man on a
darkened stage with wires on his head and his brain generating music was surely
impressive enough, but Lucier was considerate in his approach applying deeper
mapping considerations to increase the sonic possibilities. The input to the system
was alpha rhythms produced in phrases of varying duration, and this one limited
parameter from the brain was carefully utilised. The amplitude was operated by a
manual control (either by an assistant or by Lucier himself) and mixed between
individual speaker channels. The known behaviour of these three parameters
(duration, volume and channel mixing) in response to alpha activity was used to
design the output stages of the system, or the musical engine, instrument type,
speaker placement, and the involvement of extra materials, such as cardboard boxes
or metal bins. Additionally, a threshold switch was used for alpha above a certain
amplitude level to trigger pre-recorded tape loops of alpha activity, transposed
upwards into the audible realm for the audience to hear.
