Concert Poster


Signal Transduction

Written for Ensemble Synapse, a group of 15 musicians who perform without a conductor, Signal Transduction was inspired by the musicians’ closer interaction. It is also a single slow movement inspired by Gagaku, the music of the Japanese Imperial Court. The flute in particular reflects the influence of music for the shakuhachi (bamboo flute).


The harmonic material is restricted to a single progression through twelve transpositions of the major seventh chord. Beginning at a high register, each new chord extends the lower pitch limit downward. The chords of the progression are overlapped so that the pitches of the next chord are gradually introduced while the pitches of the previous chord are filtered out. This results in an alternation between the consonance of a single major seventh chord and the dissonant superposition of two transpositions of this chord.


The piece shares with Gagaku a predilection for abrupt interjections of contrasting character; here these are more unconventionally used as framing devices.  Silence, two chamber music sections, and several bursts of comical-violent music are used to destabilize the dominant musical state of sustained meditation, and actively trigger a deeper understanding of this meditative state. 


A trio for oboe, piano and viola appears just before the middle of the piece and marks the moment when the rhythmic pulsation acquires more linear contour.  At this point, the rate of harmonic change increases exponentially.  In consequence, less time is possible for transition material, and sectional divisions become more abrupt. 


The composition explores different roles of texture: suspended, held pitches, enlivened static pitches that pulse at various speeds (rhythm without pitch movement), and also pitch movement that is restricted vs. gradually liberated.  Throughout the composition, these textures switch roles in terms of musical perspective (foreground, background).


In science, signal transduction is a form of communication between nerve cells and is the essential brain function. Cells pass their signals to other cells, sensory impressions are processed, and thoughts are stimulated.  Cells that pass on information are electrically stimulated, whereupon they release chemical transmission compounds known as neurotransmitters.  The firing of neurons (or nerve cells) takes many forms, pulsing short and fast, or constant and drawn-out; they occur simultaneously through the signal transduction pathway.  In this composition, one may perceive each musician as a nerve cell whose signals are single pitches, communicated multifariously to other musicians and, inevitably, to the listener (in this way, the musicians’ responsibilities are non-hierarchical).  On a larger scale, the harmonic structure is the transduction of one signal that lasts the entire piece, the signal being the intervallic content of the major seventh chord.  One may perceive the twelve chromatic steps as the cells, which pass on this one signal through the entire chain. 




Ce fût un plaisir de travailler avec Emily sur le projet Signal Transduction. Emily n'a pas peur de donner du travail aux musicienn et exploite les capacités de divers instruments avec brio. Elle a su intégrer des influences de musiques folkloriques asiatiques à son language propre ce qui en fait une oeuvre nouvelle mais qui a des racines bien accrochées dans l'histoire.


-Vincent Parizeau, bassoonist (NAC Orchestra),

Founder of Ensemble Synapse

Canadian Composer Emily Hall / Compositeur canadienne Emily Hall

                                                    Email / Courriel: Emily Hall