Lowell Cross' original design for Reunion¹ featured sixteen audio inputs, four for each of the four composers. These inputs were connected in a fixed but random way to eight outputs - the eight speakers surrounding the audience. Each input was connected to four of the eight outputs. Through the use of photoresistors, the squares of the chessboard acted as switches on these connections to turn them on or off, depending on whether a particular square was covered (by a piece) or uncovered. How covered/uncovered was mapped to on/off depended on the position of the square. In order that the initial position was `silent' the first and last pair of ranks (or rows) were off when covered, on when uncovered. The remaining ranks were on when covered, off when uncovered.

We have created two versions of Reunion, one intended for use over the internet through a web browser, the other for live performance.

The online version aims to model the real version as closely as possible, within the restrictions of what can be delivered via the internet to a modern PC or tablet. We retain the sixteen inputs, but stream pre-recorded music rather than live performances. As the majority of modern computers only support stereo output, we simulate the eight physical speakers in the original by defining eight virtual speakers at different positions in the stereo field, each with a given volume to simulate distance. Like the original composition, each input is mapped to four of these virtual speakers.

As per the original, the chessboard squares act as switches on these connections, and we retain the overall scheme of having the first and last two ranks switch on when uncovered and the remaining ranks switch on when covered. The original mapping between the audio tracks, chessboard locations, and speakers was chosen randomly, and has not been recorded. Rather than produce a single mapping, we generate a new unique mapping for each use, providing a unique experience for every user. With over a googol (1 followed by 100 zeroes) possible configurations, this means every user gets his/her own unique interpretation.

Cross remarks, "Ancillary effects of sound choices and motion resulted from the shadows of hands and arms as the players moved pieces.”² We do not simulate these at present, but in principle they could be added either randomly or through an analysis of where shadows are likely to fall for a given move.

The online version of Reunion is built using HTML5, a language implemented by all modern web browsers. HTML5 provides the ability to play and pan the sixteen tracks of sound necessary, and provide a chess game, all within a web browser. Furthermore, it supports play between two humans, or one human against an artificial opponent. Thanks to Stefano Gioffré for providing his HTML5 chess engine for public use. For people with less powerful computers or slower internet access, we provide a scaled-down version that plays fewer music tracks and/or uses a lower bitrate, aiming to provide the best experience possible.

The live version of Reunion more closely matches the original, supporting eight physical speakers through a sound card attached to a computer. We do not use photoresistors in the chessboard to switch the connections defined in the computer, but instead enter the moves into the computer as they are made.⁴

Chris Jefferson & Ian Miguel

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