It's been a labor of love for Metallica as they're approaching the final phases of working on their long-awaited successor to 2008's Death Magnetic. The album has been confirmed to be in the mixing phase and Metallica's Met Club fan club recently interviewed bassist Robert Trujillo, who gave some exciting news concerning the new record.

When asked if he can provide an update, Trujillo happily reflected on recording backup vocals, stating, "I can say James [Hetfield] and I had a blast doing backup vocals last week [it is not known when this interview was conducted], it was probably the most fun I’ve had during this album cycle, I wouldn’t even call that work."

Expanding on what made this so much fun, the bassist continued, "It was just super fun blasting out those choruses; he had a big smile on his face and so did I, so that’s something that I’ll always remember because I don’t think I’ve ever done it on that level. I mean, we’ve done a couple things here and there, but that was a first for me, to be in the vocal booth with him. It was pretty cool. So I feel great."

Talking about his musical contributions, Trujillo beamed, "The bass sounds are crushing. I would say they’re the best bass sounds that I’ve had with this band for sure, and already for me that’s a plus. I’m very proud of what Greg [Fidelman, producer] has done with the sound of my instruments and I’m also proud of the way I played. We’ve had fun."

Before Christmas, James Hetfield shared a sample of new Metallica music from the studio, giving fans the first glimpse at what the thrash icons have to offer. Recently, drummer Lars Ulrich told Citizens of Humanity, “Hopefully it’ll be out in the fall, and it definitely sounds like Metallica." Detailing the difference between this album and Death Magnetic, he went on, “It’s probably a little less frenetic than the last record. The last one Rick Rubin really encouraged us to for the first time be inspired by our past. It was the first time we sort of looked in the rearview mirror." He wrapped up, "...we’re expanding a little bit on the sonics. It’s probably a bit more of a diverse record than the last one.”

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