Katy Perry dropped a one-off single in 2016 ... We can't even go to the park without coming out in a rash. Katy's Egyptian epic Dark Horse has been watched nearly 1.5 billion times on YouTube.

Pop star Katy Perry has announced the American leg of her The Lifetimes Tour, which will bring the "Dark Horse" singer to Nashville this summer. On Perry's first tour in over seven years ...