Rbow, constructed by Dan Trueman and
Perry Cook, consists
of a traditional violin bow with motion sensors (a biaxial accelerometer,
mounted at the frog) and pressure sensors (mounted between the hair
and the stick in two locations). It can be played by itself, using
the shoulder or other surface as a point of resistance, or on any
violin. Trueman uses it primarily with a six-string, solid-body
electric violin, and in combination with pitch, amplitude, and overtone
detection of the electric violin signal.
Rbow was motivated by Trueman's frustration with conventional interface
devices available to the violinist; footpedals seem crude and awkward
as expressive instruments in comparison to the bowed string. By
itself, the Rbow suggests a variety of kinds of physical interaction
with electronic sound; moving the frog in various positions, which
may require moving the entire body, and simply pressing the bow
in various locations, all are effective ways of physically playing
this way, the Rbow transforms the violinist into a kind of dancer,
and requires Trueman to modify his traditional violin technique.
When played with the electric violin, this often creates an interesting
technical conflict--certain techniques, while effective for the
Rbow, may be useless for playing the electric violin, and vice-versa.
Finding points of cross-section, where playing both instruments
simultaneously is physically and musically fulfilling, is one of
the fascinating challenges presented by the Rbow.
Rbow also offers mapping flexibility; the sensor data can be interpreted
in many ways, and these interpretations can change over the course
of a performance, phrase, or even within a gesture. One particularly
compelling mapping attaches virtual shakers to the bow, encouraging
the performer to shake and gyrate in various ways to control the
energy and resonances of the shakers. In combination with analysis
of the violin's audio signal, the Rbow makes for an effective controller
of both physical models and realtime granular delay techniques;
Trueman makes extensive use of the PeRColate
toolkit in MSP which includes both of these kinds of synthesis and
signal processing techniques.