Information Technology Reference
In-Depth Information
The level of depth attained within these mapping strategies requires a high level
of mental concentration and awareness of time, external and in relation to the music
within a performance. Here, the mappings had to be tested, learned, practiced and
optimised for system performance and user ability.
The Warren
demonstrated that BCMI technology could be used in place of more
traditional digital controllers as well as in a live performance setting. In 2013s
Flex
(Eaton and Miranda
2013a
), this idea was taken a step further through a BCMI built
using affordable hardware and open-source software. In an effort to make music
making with brainwaves more accessible,
Flex
used SSVEP with an EEG headset
by Emotiv and two laptop computers, one providing the visual interface, EEG
signal processing and transformation algorithms and the other the musical engine.
The gap between compositional and mapping design used in
The Warren
was
disregarded here as the two elements were intertwined.
Flex
is designed to be
between approximately 10
15 min long depending on the how the controls are
found and used. The composition combines sound sources recorded in surround
sound, ranging from fairground ambience to bell chimes, with synthesised and
heavily processed sounds. A key aim of the performance is to convey the narrative
of the composition whilst attempting to engage an audience with the control tasks
being undertaken by the performer.
Flex
uses the idea of control as a key theme. Instead of merely providing control,
Flex
hides control and moves it around forcing the performer to adapt to the system
and learn control before it is taken away again. In effect, the controls corresponding
to the icons are randomised; different elements of the composition are presented
without any way of the performer knowing in advance. Built-in rules allow for the
presence of mappings corresponding to the current sounds being played, but the
choice of parameters is selected at random from an array of predetermined func-
tions. Performed in quadraphonic sound, mapping rules mix the sounds across the
four channels as well as control the arrangement of the piece. Additional mapping
rules control micro-level functions such as audio sample playback and audio effects
(Fig.
10.8
).
Indeed, there are more mappings available that can be used in any one perfor-
mance, which helps make every performance different. The line between active and
passive control becomes somewhat blurred here due to the manner in which control
is attained. Control in
Flex
can be dif
-
cult to establish, and this brings elements of
the unexpected and even the undesired into a performance. Again, hidden sec-
ondary mappings are also built into add elements of surprise, in effect further
flexing the rigidity of control throughout the piece. Overall, the mapping system is
designed for control to be manageable, and where control becomes lost, it is rel-
atively easy to recover. As such, certain safety features are implemented in order to
prevent complete chaos. Performing
Flex
becomes a musical game, where the aim
and reward are control (although the success rate of control is not a primary
concern) and where the audience is rewarded with the resulting music and
performance.
One of the main issues with performing with a BCMI system is what could be
considered as a lack of obvious
'
performance
'
. EEG measurement
requires
