Metallica bassist Robert Trujillo spoke at length with Rolling Stone recently about lengedary jazz bassist Jaco Pastorius, and the film he co-produced, Jaco: A Documentary Film. Of course Trujillo was asked if the new Metallica material felt like an “extension of Death Magnetic,” but Trujillo couldn’t say.

“I really can’t relate it to any album; I think every Metallica album is unique in its own way. What we’re doing is special and unique in its own way, but still keeping it heavy. For me as a listener, part of the journey I’m on with Metallica, there’s just a certain edge that needs to be there. Before I even joined Metallica, I used to train for tours, when I was in Suicidal Tendencies, to Ride the Lightning. There’s nothing like jogging the trails to, like, “Fight Fire With Fire.” I can tell you that what we’re doing sounds heavy, but again each album is its own little experience. So we’ll just have to wait and see.”

Drummer Lars Ulrich was just as vague last month in his interview with Rolling Stone, saying, “we’ve got lots of songs, and we’re honing them and tweaking them. It’s pretty close.”

The only thing we know for certain is that Metallica will be returning to play Lollapalooza in Chicago, IL this summer, something they haven’t done since the release of Load in 1996.