abstract
Resonances in brass instruments are created not through blowing streams of air through the instrument as might be logically inferred, but rather using an air stream to vibrate the lips, which in turn resonate the air already present in the instrument, resonances which then radiate outwards via the bell. In Incursion, a work for solo extended tuba, a feedback loop system provides an additional source of resonation for the air contained within the instrument, which, given the fact that it does not rely on use of the lips, can radiate outwards via both the bell and the mouthpiece.
Following a long-term collaboration between composer Luciano Azzigotti, and tubist Jack Adler-McKean, the piece forms an initial artistic realization of the development of two microphone-based sonic interventions. A piezo-electric microphone is connected to a modified fourth valve slide, which is connected to an amplification pedal, and outputted to a loudspeaker which is suspended inside the bell by means of a 3D printed mount. By depressing the fourth valve and opening the connected valve chamber, it can therefore create a feedback loop resonating inside the valve loop itself.