Recorded music creation and consumption underwent a huge shift in the first two decades of the 20th century: from physical artifacts to digital; from fixed personal computers to mobile devices; from downloading and owning to streaming and access. This had a significant impact on the music 'assemblage' - the audio, performances, videos, films, books, games - that make up what we think of as 'music,' and gave rise to new forms of musical new media. Björk's Biophilia, widely acclaimed as the first 'app album,' is one response to this context. Drawing on her direct experience as part of the creative team who made Biophilia musicologist Nicola Dibben investigates how popular music practices intersect with digital technologies at their moment of emergence in two domains: music software applications ('apps') for touchscreen technologies of tablet computer and smartphone, and in extended reality. She shows the way these new media formats maintain musical traditions as much as they innovate, explores the future of the album as a musical artifact in the digital age, and identifies emerging new music forms and engagements which may come to define our digital musical futures.