Arctic Monkeys' shift to a piano-based sound for their new Tranquility Base Hotel + Casino LP is sure to catch more than a few listeners by surprise. But for frontman, guitarist and principal songwriter Alex Turner, the move was nothing short of necessary.

"The guitar had lost its ability to give me ideas," Turner explained during a recent BBC interview (via NME). "Every time I sat with a guitar I was suspicious of where it was gonna go. I had a pretty good idea of what it might be, which is completely contrary to what I felt when I sat at the piano."

Fittingly, Turner's newfound compositional freedom took him straight into space — at least thematically. The Tranquility Base material has a science fiction slant, something he explained by saying he'd immersed himself in the genre while he was writing songs for the record.

"It might have had something to do with some of the stuff I was reading and films I was watching around then," he added. "I think it started with the idea of science fiction and the worlds that are created in it or the idea of space travel, time travel or whatever it is, is used to put out an idea about the world we’re living in."

To celebrate the imminent release of Tranquility Base Hotel + Casino, which arrives in stores today, the band put in an appearance on The Tonight Show Starring Jimmy Fallon on May 10. Check out their performance of the new song "Four Out of Five" below.

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