Hum began after I started to think of my installation as performative, my installations as events where audience members would play these closed systems as an instrument, not just play within them. Thinking this way I saw training performers to use one of these instruments as a possible way to re-inject a score back into my work, which had not been present since working with more linear media.
 

The system in Hum is an instrument which is collectively played by four performers as opposed to four performers playing separate instruments together. Each one is a sine wave, the frequency of which is controlled by the frequency of their pulse and the level of which is controlled by a hand gesture. The Timbre of the sound is then changed by these variables and the patterns they form by plugging themselves into each other using cables and inputs on their belts. In this implementation of FM synthesis there is a perpetual drone which is controlled by the performers. It is these individual sound vibrations creating this drone or hum which gave the piece its’ title. So the instrument is played by changing the timbre of the instrument as opposed to playing notes or chords with a set timbre.

As well as controlling sound, the performers also control the details of a projected image as I remain off stage cuing the movement from one graphical scene to the next. I had not originally thought of myself as a performer when beginning the project as I was outside the feedback loop of the system I had created for the performers, yet I was within one of my own. A UV flood light was also used to illuminate the cables and patterns between performers. The variation in the projected light, which is cast across the stage then competes with this lighting and creates a play back and forth between darker moments where the patterns between performers are the focus and lighter moments where the image and the details of the movement are the focus.

The choreography deals with themes of power struggle within this collective creation, tapping into my political views on ‘open source’ as a starting point for the simple archetypal characters which drive the structure. The movement began by letting the performers improvise with the instrument as Christin Sell and I selected moments to shape into a more structured form. The sound deal with the theme of frequencies and noise as a metaphor for life and creation, the individual frequencies of the performers’ pulses coming together to form a collective pulse which feeds this digital creation.

The piece begins with individual solos, then performers solo in pairs and then as a group. The heterodyning during the paired solos is the beginning of a more complex soundscape. This heterodyning would vary with the drifting relationship between the two performers’ heart rates. Both their movements and heart rates would drift in and out of phase with each other and with the sound.

The performance in this first incarnation fit into a traditional three act structure within the proscenium space. However, at a later exhibition where documentation of this piece was shown another audio only version was performed which did not require my performing. The performers used the instrument as before but were given complete freedom with their timing and movement. This was rewarding to see, as although they were not audience members, they did tap back into that spirit of play which has been motivating me to make interactive systems. However, their improvisation was much more well informed than when we first started working together. Over the weeks of rehearsals they had truly learnt the repertoire of this instrument, the cables now functioning as an extension of their bodies. This version of the piece became like a ‘contact improvisation,’ only that all the contact was through the cables and not through direct touching of each other. It was also great to see the performers take it upon themselves to interact not only with each other but with audience members within the gallery.

TECH SPECS

An Athlon XP running Demudi Linux 1.2.1 with Pure-data 0.37 and the following libraries; Cyclone, OSC (Open Sound Control protocol) and Comport.  The Athlon is connected via ethernet cable on a closed network to a G5 running OSX 10.4 and Pro- cessing 0111 with the OpenGL and OSCp5 libraries. Performers have flex sensors and heart rate monitors made from an LED and a light sensitive resistor feeding into boxes on their belt containing custom electronics using PIC microcontrollers programmed with P-Basic and powered by a 9 Volt battery. Their data is output as bytes to a 9 pin serial to male BNC cable to connect to other performers. The data is sent from each box as a series of bytes: current box number, heart rate data, flex sensor data, boxes connected to inputs. The data from boxes connnected to the inputs was also passed through in this form to enable ac- curate routing in Pure-data.

A similar box minus the sensors was contained within an obelisk for the performers to plug into and send the data to the Athlon via a 9 pin serial port. Pure-data then received this and processed the sound, sending it to a PA system before sending filtered information across a closed network via OSC into Processing to control the graphics, which were being output to a VGA projector. A 400 W UV flood light was also cast across the stage.