s.laag is an interactive work especially composed for Dutch Bass Clarinettist Marij Van Gorkom, as part of the Dutch-UK.network project started in 2015. The piece explores the concept of "Extended Reality", taking place in the intersections of the Real, Virtual and the Modular Augmentation of a musical instrument. The environment is the Expo 58 in Brussels, where Pavilions from different nations become the stage for the bass clarinet. The player needs to dis-embody and re-embody the musical instrument which transforms itself into a new self (mobile, parts, human-like) unfolding new degrees of musical expression.