Metallica have revealed that they're debuting new music at their South American concert this weekend. The band posted to their official Facebook page revealing that they were "Working out the kinks in the new song that we'll be debuting in South America in a couple days." The band has a gig set for Bogota, Colombia on Sunday, which is the first date of their South American tour.
They also referenced the song on Twitter, with the following:
Metallica ✔ @Metallica
Jammin' on a new tune at HQ and getting it ready to go to South America in a couple days.
7:18 PM - 13 Mar 2014