We're heading to Vegas on this week's edition of CMT Hot 20 Countdown. Tune in as we rub elbows with the stars at the iHeart Radio Music Festival. We're chatting with Eric Church, Zac Brown Band, Taylor Swift and more at the event. Plus, Carrie Underwood talks about her motherhood fears and Jason Aldean opens up about private moments that made headlines. And see where Blake Shelton's brand new video, "Neon Light," debuts on the countdown.