Terry Riley’s In C (1964), the seminal minimalist work composed for an indeterminate number and unspecified ensemble of musicians, presents a unique set of challenges in the context of distributed performance. The pulse of the piece is calculated and distributed to match network delay between connected sites, ensuring that the rhythmic patterns that comprise the piece are tightly synchronized, albeit shifted a number of metric beats, ensuring the musical result is different at each end of the performance.

The 2009 performance of In C at the MiTO Festival was distributed between Milan, Stanford California and Missoula Montana. While previous performances have included traditional instruments and laptop performers, this rendition added virtual world avatar performers and a novel method of moving one’s instrument through Riley’s composed musical pathways. The orchestra consisted of Piano and Avatar/Laptop performers in Milan, Avatar/Laptop performers and violin in Stanford and Celetto and Electric Violin in Missoula. The ensemble was synchronized through a metronome that generates audio and OSC messages.

In C is designed in a manner that lets musical performers move linearly through composed musical cells, choosing repetition and cell-onset timings while remaining strictly locked to the underlying metronomic pulse. The virtual environment artwork was created as an allegory of the work, sequentially following a set of patterns or cells though motion down a rendered pathway. A clear linear pathing model was used, so that each cell of the modular music was likewise represented visually as the cell of a pathway.

As multiple performers were connected from disparate global locations, separate paths were created so that the physics bounding box would hold everyone on the paths, and prevent anyone from literally “falling off” the perfor- mance path. The journey took the audience through a sur- real floating city landscape with an end tower clearly in site for all 3 paths. This conforms with the instructions of the piece where at the end the whole ensemble “lands” on the last pattern.

This rendition of In C adds different layers of musical and visual meaning that conform with the original intention of the piece, and it’s an example of multi-modal expansion of existing repertoire. The idea of local synchronization is expanded to distributed musical synchronization. The idea of advancing to a series of musical cells is not only illustrated in the virtual world, but literally this is performed, i.e., physically advancing means musically advancing in the cells.