This video has been produced as part of a 2015 internship program at the University of Salzburg, Austria.
Four summer interns of the Computational Systems Group lead by  Professor Christoph Kirsch arranged the song “Bad Romance” by Lady Gaga in a software tool called Antescofo which follows the score and accompanies the musicians in real time. The video provides captions with the details.
Have a look what they did: Video