Gwen Stefani previews Spark The Fire produced by Pharrell Williams

Gwen Stefani has visited some radio stations in the United States to promote her newest single, "Baby Do not Lie".

Passing through the station 97.1 in Los Angeles, the singer released a preview of "The Spark Fire", previously unreleased track in collaboration with Pharrell Williams, who also produced one of her biggest hits, "Hollaback Girl".

The song will also be on her next album, which is expected to come out in the first half of 2015.

Check out the excerpt below: