Treader (2009)
Compensating-system tuba
Treader is one of a series of pieces to draw on the 'noise-valve' technique, in which the piston valves of the English E♭ tuba are rotated rather than pressed, changing their traditional function of altering pitch to one of producing noise. The piece actually draws on a combination of this technique and the traditional piston valve technique – whilst one valve is gradually rotated, another valve is pressed and released in the traditional manner. As air is only able to flow through the instrument for the split second in which this valve is in halfway position, this results in a series of percussive impulses as the valve is pressed and released. The gradual rotation of the other valves leads to micro-variations in timbre, reminiscent of the alteration in the acoustics of the same impulse as it passes through different acoustic spaces.
The full piece appears on the solo CD/LP States of Rushing, released on Choose Records in 2009.