In the three-minute clip, Winehouse can be seen singing a cappella, headphones on, to the backing track as she lays down the song inspired by her on-again/off-again relationship with future husband Blake Civil-Fielder.

"It was just one of those serendipitous things," Ronson said. "I caught her at that magic moment. She was ready to get it going, that's why I couldn't understand what everyone else was saying about this procrastinating, troubled artist."