Shakira is a huge Metallica fan.
The 'Whatever, Wherever' singer grew up listening to heavy rock bands, and has a particular fondness for the 'Enter Sandman' group, so has been including one of their songs at recent concerts to surprise fans.
She said: "I am great fan of bands like Led Zeppelin, Nirvana or The Cure. I used to be a huge Metallica fan when I was 15, 16 years old.
"I remember I was graduating from high school back then and I used to sing 'Nothing Else Matters' all day long. I am still a very huge Metallica fan, though.
"So I thought it would be kind of surprising to include it in my repertoire for this tour."
Shakira's career has seen her push the boundaries of pop music to great success, singing in both Spanish and English and covering a number of different genres. She also recently said she would consider recording a song in Arabic, although she has yet to learn the language.
She said: "It would be a challenge to do an album in Arabic, but I would first have to learn Arabic.
"I am completely open to that experience - at some point I would love that to happen in my life."