"I'm on my laptop on a little four-day vacation in Mexico," Lambert tells Billboard, "and I open up my iTunes, I'm searching through, and I'm like, Oh, Madonna's music is out! I love Madonna! I've always loved Madonna -- she's an icon, she's an amazing entertainer. And I see on the track listing a song called 'Ghosttown.' And I thought, What are the chances? What is the hell is going on here?"

At first, Lambert panicked a little. "My reaction was so complicated," he says, "because I think I texted my management, like, 'Did you see this? Did you see this? What are we gonna do?' And they said, 'You know, it's fine because the songs are so different.'