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ections on the piece, Lucier recognises the importance of how his
mapping choices are linked to musical complexity. He even goes as far as to
identify a further mapping strategy, unavailable to him at the time. He wished to be
able to store time-encoded sections of alpha activity and map patterns within them
to speaker channel mixing; a technique possible with today
In his re
s computing and not too
dissimilar from methods used in BCMIs discussed later in this chapter.
In contrast to Lucier
'
s desire to communicate the natural frequencies of brain
activity through acoustic and tangible sound sources, Richard Teitelbaum, a
musician in the electronic ensemble
Musica Elettronica Viva
(MEV) began to
incorporate bio-signals into his electronic compositions using modular analogue
synthesisers in the 1970s. Taking inspiration from Lucier and new advances in
synthesis technology, Teitelbaum integrated EEG signals alongside other bio-sig-
nals into his pieces, many of which focused on the use of meditative states of mind.
Performed throughout 1967
Spacecraft
was Teitelbaum
'
ed EEG
activity as a control voltage (CV) signal for a Moog Synthesiser. Here, the electrical
activities of the brain were electronically soni
'
s
first use of ampli
ed in real time, again providing a
real-time biofeedback loop for the performer (Teitelbaum
2006
). Although
Spacecraft
was a wholly improvised composition, it provided a foundation for his
later uses of brainwaves that sought to investigate elements of control and musical
interaction.
In Tune,
perhaps Teitelbaum
first performed in Rome,
1967. What stands out in later versions of the piece (referred to by the composer as
the expanded version of the piece) is the introduction of a second performer
'
s most popular work, was
s EEG
within his system. Alongside other bio-signals, including heartbeat and ampli
'
ed
breathe, alpha activity was measured and then split into two paths within a modular
system comprised of analogue synthesis modules, a mixer and audio effects. Before
any audio processing took place, a threshold gate was set to allow only alpha
signals generated with eyes closed to pass; the amplitude of alpha rhythms is
markedly increased by closing one
s eyes. This provided a simple control switch for
performers; system ON with eyes shut and system OFF with eyes open. Precise
control within an ON state of the system
'
s parameters was largely unattainable
beyond basic changes of alpha amplitude increase and attenuation. With the gate
open, the alpha of a performer was split from an envelope follower into two
directions within the system to provide a one-to-many mapping. The
'
rst path
allowed for a direct DC signal to be mapped to two voltage-controlled oscillators,
thus modulating a preset centre pitch for each. The second path sent the EEG signal
to an envelope generator, which allowed for variable control of a voltage-controlled
ampli
er (VCA) and voltage-controlled
filter (VCF). This parallel mapping of one
EEG signal allowed for real-time modi
cation of pitch, rhythm and amplitude of
the synthesised waveforms coupled with magnetic tape recordings being played
back through the same VCA and VCF. Again, these mapping choices were not
arbitrary but were in keeping with Teitelbaum
s artistic aims for the composition.
The heavy breathing and sexualised moaning sounds played back from one tape
machine being rhythmically enveloped by the alpha were designed to play along-
side the live breath and vocal sounds from a throat microphone (Teitelbaum
1976
).
'
