This has been rumored for quite a while now, but it looks like it's confirmed, according to E Online:

Johnny Depp is currently filming the upcoming flick Lucky Them in the Seattle area, and he surprised small-town fans when he serenaded locals in the town of Carnation while taking a break from work.

Congratulations to Lucky Them director Megan Griffiths for landing Depp for her movie. I'd like to think Griffiths's Stranger Genius award helped make this possible, although I have no idea how that could possibly be.