"Promiscuous" by Nelly Furtado

Nelly Furtado had built her early-2000s name on earnest, breezy folk-pop — a world away from where radio sat in 2006. For her third album, Loose, she went into the studio with Timbaland and Danja, and "Promiscuous" arrived on April 25, 2006, ahead of the album's June release. Written by Furtado with Timbaland, Danja, and Timothy Clayton, and produced by Timbaland and Danja, it was the reinvention made flesh.

The song itself is pure flirtation: Furtado and Timbaland trade lines in a call-and-response that plays like genuine banter over crisp, urgent production. It hit exactly as the season turned and simply would not move: six weeks at #1 on the Billboard Hot 100, Furtado's first US chart-topper and the first by a Canadian female artist since 1998. Critics widely called it the highlight of Loose.

It earned a Grammy nomination for Best Pop Collaboration with Vocals — losing to Tony Bennett and Stevie Wonder's "For Once in My Life," a loss that felt beside the point. "Promiscuous" had already done its job: it announced that Furtado wasn't the artist she'd been, and it fixed her new sound to the summer of 2006 so completely that the opening bars still teleport a generation straight back to it.