Kelsea Ballerini Wows as the country’s next big arena star

“How Do I Do This,” a sing-along for 12,000 people, addressed the anxiety of dating again after a breakup. “Blindsided (yes, sure, okay)” asked, “Were you blindsided, or were you just blind?” The requested “left me again” wished him well, and for her own sake I wished some self-love: “I hope I never leave me again.”

And she packed a bad marriage’s worth of baggage on the encore of “Penthouse” with just her voice and piano as she crooned, “I guess wrong can look good/When you’re playing home in a penthouse, baby.”

Opening the rare all-female country program were two little-known singers: Sasha Alex Sloan (Rhymes with Sacha Baron Cohen, the comic/actor), a talented Boston-bred indie-pop singer whose low-energy but well-crafted songs would be better suited at First Avenue ( where she has played); and Marynn Taylor, a promising country newcomer from Michigan signed to the same Nashville label that Ballerini records to.