Iris ter Schiphorst's  "KONZEPTE zu FLÄCHE(N)" (concepts of areas) is a detailed concept piece which radically questions the concepts of music as a sound phenomenon, of composition, of performance practice/concert practice and common rehearsal practice and, in accordance with the "concept art" definition from the visual arts, explores new horizons. A work that potentially provides the audience, the choir and the choral conductor with completely new experiences"

http://www.datenbankneuemusik.de/datenbank/werke/k/konzepte-zu-flaechen-ter-schiphorst-iris.html

An example of an independent development, here the Landesjugendchor Brandenburg in March 2017 in Donaueschingen:
https://player.vimeo.com/video/220502091