— but you'd never know it from his show-stopping performances!The 15-year-old singer took the stage for his first live performance during Monday's semifinals and thrilled the crowd and coaches with his performance of Billy Joel's «Vienna,» starting on the piano before he took center stage to belt the sentimental ballad.Coach Niall Horan had nothing but praise for Ryley's performance, noting how much confidence it takes to sing and play piano on live television.«This kid is just off the charts. He's here for a reason,» Niall raved.