ISDN is a large-scale two-channel video installation that explores music as a form of cross-continental cultural collaboration titled after a technology, introduced in the 1980s, used to transmit high-quality digital audio over copper phone lines. The video installation has two screens facing each other. It stages a fictionalized account of two musical collectives on each screen, ca. 2011, one in London featuring Grime rappers Lady Sanity and TrueMendous, and another in Cairo featuring Mahraganat rappers Raptor and Joker, trading freestyle verses supposedly transmitted over ISDN lines. While the London rappers exchange 16-bar verses the performers in Cairo listen—until it’s their turn to do the same—or so it seems, even though they were recorded separately and weeks apart in their respective cities. The viewer is positioned between the two screens, caught in this call-and-response cipher unfolding across continents. The performers foreground systemic social ills in their verses, directly raising questions about race and class in their home countries. Layers of sound underneath the vocals are mixed in an ever-changing configuration, in permutations that take more than four weeks before they repeat.