"Madonna told me, 'Keep your eyes on the prize.' I was at her house in New York. It was intimidating. Her son David answered the door. I thought, 'This is so surreal.' When we talked about singing together, she said, 'I'm really bossy in the studio. I'll piss you off.' I said, 'If you piss me off, we'd probably make good art.' We bantered. She was cool."