What happens when you combine Madonna with Stuart Price and ABBA? You get one of the most fantastic pop songs of all time and as her highest-selling digital single, a great commercial success too. The song's origin was as part of a musical written by Luc Besson, but can be traced back even further to the summer of 1979 when ABBA rehearsed their tour at Europa Studios in Stockholm. Hear outtakes from that ABBA record along with the stems from the Madonna song which would hit no. 1 around the world.