But after she wrapped rehearsals — and before she got back on her plane — MTV News's special EMA correspondent Gabe Saporta caught up with Miley for a few minutes backstage at Madrid's Caja Magica, where she revealed a few details about her super-secret EMA performance.
From the sound of things, it's going to be a rather epic, eye-catching thing. And quite possibly based on the work of "Da Vinci Code" author Dan Brown.
"We actually came up with this concept because I wanted it to kinda be 'Angels and Demons,' but it's not a Tom Hanks reference," Cyrus said (referring to the star of both of Brown's movie adaptations). "It's [about the idea] that during this world, you're always going to have temptation; basically that's kind of the whole vibe."
Cyrus added that her performance will feature some elaborate costuming, some chiropractically challenging dance moves and, of course, some symbolism. Oh, and if the whole thing seems too deep for you, that's probably because you're a dude.
"It's a little more Victorian," she explained. "There's a lot of lace. The girls are dressed all in white, and the guys are in black. ... The girls will know what I'm talking about."
The 2010 EMAs will air on MTV2 on Sunday at 9 p.m. ET, and an edited, performance-heavy version will be broadcast Friday, November 12, at 9 p.m. ET on MTV.