And Souza says that, looking back at Metallica's career path, they are heading towards a more classic thrash sound on the follow-up to 2008's Death Magnetic.

Souza tells Overdrive: "If you really want to look at Metallica's progression as a band, look back to the stuff they released in the 90s with Load and St Anger and then they brought out Death Magnetic, so I would say that they are getting more back into form of that classic Metallica thrash sound.