Promoting sounds post malone or juicewrld(rip) best sad song writer

In 2008, to celebrate the release of lawrence lessig’s book, bloomsbury academic press hosted a competition called remix the remixer. entrants were asked to find a video, interview, or written work of lessig’s, mash it up with another piece of lessig’s work, and create something new, a video, photo, or text. what is this sort of artistic activity called?