The Technology in Song No 3

The set-up used for this performance is quite simple: the performer has a microphone in her hands and a loudspeaker placed over the mouth. The third main element is a computer processor in the form of a MaxMSP patch (a visual programming language for music). In short, the technical process used during the performance can be described as follows:


  1. The loudspeaker in front of the mouth diffuses a sound shaped by the MaxMSP Patch.
  2. The microphone picks up this sound.
  3. The MaxMSP patch analyses the amplitude of the microphone signal.
  4. The patch uses the amplitude of the microphone signal to control the parameters of the sound shaped by the MaxMSP Patch.
  5. This sound is diffused by the loudspeaker and everything begins again from step 1.


The process described above results in a continuous loop of feedback data. Depending on the amplitude of the microphone signal the loudspeaker will produce a certain sound. This amplitude of the microphone signal is dependent on the sound produced by the loudspeaker. The second factor that influences the amplitude of the microphone signal is the distance between loudspeaker and microphone: the further the microphone is away from the loudspeaker, the smaller the amplitude of its signal. This has several consequences: as soon as the microphone moves, the amplitude of the microphone signal will change and therefore the parameters shaping the sound will change. This will result in the diffusion of a different sound by the loudspeaker. This might change the amplitude of the signal diffused by the loudspeaker and therefore also the amplitude of the signal picked up by the microphone.


The character of these changes is variable during the piece and depends upon how often the performer has brought the microphone to the mouth already. While all the details of this parameter mapping cannot be covered here, I will show some examples:

Example 1: The loudspeaker emits a very soft sound. As soon as the amplitude of the microphone signal crosses a certain border, the patch changes the sound and makes it louder. This border will be crossed every time the performer brings the microphone to the loudspeaker in front of her mouth. As soon as the microphone is moved downwards again, the amplitude of the microphone signal is reduced and the loudspeaker emits again the original soft sound.

Example 2: As soon as the amplitude picked up by the microphone crosses a certain level, a singing voice is heard. The pitch of the singing voice changes slightly according to the amplitude input of the microphone (the closer the microphone is to the loudspeaker, the higher the sound). As soon as the microphone has a certain distance to the loudspeaker, and the amplitude level of the microphone is therefore lower, the singing voice disappears again.

Example 3: Several amplitude levels of the microphone signal trigger different sound files.

Example 4: The amplitude level of the microphone controls the speed of the playback of a sound file, with the help of a phase vocoder. A low amplitude signal plays the beginning of the sound file, a high amplitude plays the end. As long as no movement is made, the amplitude will barely change and therefore the same sound can be heard.