ResOscope

ResOscope is a sound toy and open form spectral composition. Its themes and technical approaches are influenced by, and can be related to ideas explored in SpiralSet. The work incorporates an animated interface constructed using a computer game engine, and this is used in conjunction with a sound engine designed within Max/MSP/Jitter. Similar to SpiralSet, the piece focuses on the concept of traversing through sound spectra. In this respect ResOscope can be viewed as further practical exploratory research in this area, extending and adapting the principle concerns of SpiralSet. However, there are a number of key differences between the two works. 


VIDEOS






ResOscope is an open form spectral sound toy that aims to provide the user with an exploratory and playful sonic experience. A symbolic approach to the control of sound is again adopted, and no parameter names or technical labels are included in the visual domain. The control system is more deterministic than that used in SpiralSet, as the player may navigate the virtual symbolic space more freely, moving between different sound types, and different sections of a spectrum without having to traverse through the entire sound. Movement between different sound types is less restrictive and more ‘open’, providing further compositional options for the player.



The player is presented with a top down view of the symbolic sonic play space. The space contains a set of spectral rails and a spectral playhead marker (or puck) that the player controls, moving it around the space. When the player moves the spectral puck over a spectral rail, sound is produced. Each rail relates to a different sound class, with the length of the rail representing the full set of spectral frames available for the sound type. As the player controlled spectral puck traverses along a rail, the timbre of the sound evolves. Spectral progression is directly related to the position of the puck along each of the rails, and its speed of motion. By moving the puck away from the rail the player may stop the production of sound. By moving the puck over and then off the rail at different points, varied spectrally shifting gestures can be created. This symbolic technique offers the player various compositional options relating to sound onset, spectral progression, gesture and form. The option to control sound event instigation and termination results in a very different compositional flavour to the work when compared with SpiralSet.


Simulated forces are used for spectral puck motion, creating a more fluid feel to its movement, and resulting in smoother timbral modulations. This also allows the player to create a sense of momentum when moving the puck around the play space. Spectral puck speed is cumulative, enabling the rate of spectral progression to be determined by the player. When combined, these features allow the user to create varied spectrally evolving phrases, and these can be revisited once a rail’s associated spectral features have been learned or identified. 


Spectral Layers


The player can set up to eight different freeze points at any position within the play space. When in contact with a spectral rail, these create a new spectral voice and set a central modulation point around which the timbre of the sound gradually shifts, moving within a small restricted spectral region. Slight modulation of spectral location is incorporated to create subtle shifting spectral effects. Simultaneously using a number of freeze point markers allows the layering of shifting spectrums, enabling the end user to create and explore a variety of different timbral, tonal and harmonic relationships.

 The user adds or removes freeze points using the spectral puck. When a desired spectral vantage point is discovered and located by the player, a freeze point may be added using a single button click, introducing a freeze point at the spectral puck location. Each freeze point may then be simply removed by placing the puck over an existing freeze point,and then using the same button click to eliminate it. These simple features allow the player to create different combinations and densities of either the same source spectrum, or multiple different spectra by placing freeze points on different spectral rails.


Spectral Set Selection


A group of six rotating spheres is located at each end of the spectral rails. These allow the player to select different sound types (spectral sets) for each rail. If the spectral puck collides with a sound type sphere, the sphere illuminates signifying that a new spectral set has been assigned to the rail. A total of 48 user selectable sound types are available, allowing exploration and combination of varied spectra. No visual clues are provided indicating the differences in timbral characteristics of each spectral set, or allowing each sound type to be identified by the player.


Circumrotate Modes


Automated rotation of the ResOscope structure may be triggered by the player. This feature, when combined with the spectral puck and freeze point markers, results in the structure acting as a form of sequencer, or spectral event generator. Different types of rotation are activated using the eight circumrotate icons found around the perimeter of the structure, (see “s” in Figure 9). When the player moves the spectral puck over one of these icons, the structure is set into motion. The structure rotates in different directions, its speed often accelerating and decelerating. Rotation behaviour is different for each circumrotate icon, and the player is again given no visual clue that allows them to deduce differences in rotation behaviour. As the structure rotates, each spectral rail may come into contact with the spectral puck, or any previously instated freeze points. On contact, sound is generated according to the spectral rail type (and player selected spectral set), and the contact point. When contact ends, the termination phase of the sound event is triggered. The circumrotate modes create a sequence of spectral events in which tempo is determined by the rate of rotation, and as this frequently accelerates or decelerates, a consistent metric structure is not established. The spectral event generator facilitated by the circumrotate modes adds a further compositional dimension to the work. 


Sound Engine


The sound engine uses an alternative spectral technique to that implemented in the SpiralSet project. Whereas SpiralSet uses additive synthesis as its primary method, ResOscope integrates a Jitter based phase vocoder with frame interpolation, used with a specifically composed and compiled library of sound materials that are used as the spectral sources in the work. The positions of the spectral puck and freeze points in relation to each spectral rail determine spectral location (frame) in the phase vocoder. Spectral interpolation is also used to further extend and blend sound materials, providing a broader range of spectral possibilities.

Control data is sent from the game engine to Max and mapped to the relevant control parameters. Index values are generated in accordance with the spectral rail that the spectral puck and freeze points are currently in contact with, and the player selected sound types. These determine which sets of spectral data are loaded (as Jitter matrices) into each voice of the sound engine. Distance values are also sent to Max which are used to identify the positions of the spectral puck and freeze points along each rail, determining spectral location within the spectral set. 

Sound materials are diverse in their origins, and sounds from both acoustic and electronic sources are incorporated. Potential sound types were analysed and converted to Jitter matrices, then loaded into the system and tested. Similar to SpiralSet, an abstract textural approach is evident in the sound world. Harmonically rich materials are used alongside more ‘noisy’ spectrums to achieve spectral contrast, and offer the player a broader range of sonic possibilities. 


Structure


andy@dysdar.org.uk                                                                                                                                                                                                  © 2014