Oxides focuses on some of the non-pitched sounds that the saxophone can produce, such as air sounds and key clicks. In fact, the entire movement is performed without a mouthpiece on the saxophone. The saxophone can produce interesting ‘noisy’ sounds, but they are often soft in comparison to normal playing. This movement uses a novel microphone technique to allow the computer to ‘zoom in’ on these smaller sounds. We attached a contact microphone to the saxophone’s body to capture key sounds, and I am wearing a headset microphone to capture air sounds. Using two microphones allows us to amplify and manipulate the two sounds independently.

The movement begins with air sounds and a ‘glitchy’ reverb. Key clicks are added as the movement progresses, eventually taking over the texture. The key clicks then pass through several different types of sound manipulations that are applied to the unpitched percussive sounds picked up by the contact microphone. The movement ends dramatically with five increasingly powerful key clicks that generate a pitched sound in the electronics.

Organic decay evolved from the idea of 'fattening up' the sound of the soprano saxophone by shifting down an octave in pitch. The computer's response is effectively synchronous with the saxophone, giving the effect of a shadow or undertone to the saxophone sound. We used the term ‘subharmonics’ to refer to this type of sound manipulation.

The movement begins with quick trills and staccato notes, with the computer shadowing my sound. The computer is always beneath the saxophone, no matter how fast or short I play. This shows how the computer can be an agile counterpart to acoustic instruments in real time, when the latency is low enough. As the movement continues, a cloud of distortion begins to compete with the saxophone line, leading to a climax and fragmentation of the opening material. The energy of the system returns to baseline as the pieces continue to break down into smaller fragments. We named this movement ‘organic decay’ to represent the process of breaking down into smaller and more elemental pieces over time.

Metabolic pathways explores a layering technique in which the computer sound blends with the saxophone to create a rich texture that could not be achieved with a monophonic instrument alone. The computer samples the saxophone sound at regular intervals and repeats it in various ways. When I play long notes, the sound returned by the computer has a ‘sliced’ quality. This method can add more voices as well as texture to the sustained saxophone sound. We use two instances of the slicer in this movement, which Adrián controls over the arc of the piece.

I begin the movement with a series of soft multiphonics, with the computer adding a pulsing rhythm to the otherwise long, sustained notes. Many pieces in the saxophone repertoire use these types of multiphonics, but the slicing effect adds another dimension to the acoustic sound. The second section of the piece is built around a melodic line with wide intervals, which produces a layered effect when combined with the slicer. The type of layering is determined by the length of the trail and how quickly I change notes, resulting in an interesting interplay between saxophone and computer system.