Underground Reference?

I'm not sure if this is an actual reference or just a coincidence but I was just too curious and I wonder if someone else spotted this. There's a moment in the movie, I think when they go to see the antiques expert, that the band that plays through the movie is shown playing and then the camera moves to a signpost that says Underground. I was left wondering if this is a reference to Kusturicas' Underground, in which a band plays all throughout the movie. If this is the case, I'm not sure why would they reference an obscure Serbian film unless the director is a fan, or if Underground was the movie that made "bands playing between scenes in a movie" famous. Did any Underground fans spotted this?