MacCallum held a position as Musical Applications Programmer at the Center for New Music and Audio Technologies (CNMAT) from 2008–2011. While there, he designed a number of software tools including one useful for composing and performing music with multiple, independent, smoothly varying tempos, which resulted in his composition Aberration (2010) for percussion trio, the recording of which was supported by a grant from the American Composer’s Forum, and The Delicate Texture of Time (2012–13) for eight players commissioned by the Eco Ensemble with a grant from the Mellon Foundation. In addition to his interest in polytemporal music, MacCallum’s compositional work is heavily reliant on technology both as a compositional tool and as an integral aspect of the performance of a piece. His works often employ carefully constrained algorithms that are allowed to evolve differently and yet predictably each time they are performed. He received his BM in Theory/Composition from the University of the Pacific, his MM in Composition from McGill University, his PhD in Music Composition from the University of California, Berkeley, and Postdoc, TerraSwarm Research Center (Computer Science), UC Berkeley.