Nelly Furtado Performs New Song in Portugal: Watch

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Nelly Furtado made a surprise appearance to perform alongside Timbaland and So Shy at the American Music Awards on November 22.

Performing a melodic ballad reportedly titled "Mystery," Nelly Furtado debuted the first sneak peak of her upcoming album at the Delta Tejo Festival in Portugal on July 2. The song is likely a track from her "Lifestyle" album, expected to release in 2012.

Watch below, as the R&B/pop star samples the new song, before launching into her 2006 Billboard Hot 100 hit "Promiscuous."

Video: Nelly Furtado Performs in Portugal, July 2

Although Furtado released the Spanish "Mi Plan" in 2009, she has not had an English album since 2006's "Loose," which stayed on the Billboard 200 chart for 70 weeks after debuting at No. 1.

Rumors have circulated that the singer has been working with Pharrell on her long-awaited fifth album, and Furtado talked earlier this year about working with Nas. "Just finished rough mix of my new track featuring Nas. You'll hear it soon!!! Xo," Furtado tweeted.

She has also tweeted that she is trying to finish the album in time for a 2012 release, but no official date has been announced.