At a festival in Copenhagen I got to take the picture below rather early in the morning, waiting for sunrise.
The instrument they are playing is called a lur, and they are always played in pairs, as on this picture. The instrument, a simple form of horn, originate in the Bronze age of the Norse culture, and only a few have been found.
If it looks familiar, some of you may have seen it on Danish butter packages (brand mark : “Lurpak”). Also in Copenhagen you can find a statue of Lurblæserne (Lur Blowers). In this case I saw some real life ancient instruments being played.