A BoP! is a musical instrument invented my Ompagniet, the world's northernmost student orchestra, whose members are students in Tromsø, Norway. A BoP! consists of a cylinder with a blowing-hole, similar to that of a classic flute, which is closed at one end by a lid. (A typical BoP! may be made out of a Pringles can.) By blowing into the hole, the lid pops off creating a distinctive sound: the BoP! The distinctive BoP! sound is a perfect finale to a tuba solo. The originbal BoP! has spawned such versions as the FlügelBoP!, the ContraBoP!, the SignalBoP! and the BagBoP!. The popularity of the BoP! is rapidly spreading, and it had become a big hit in Scandinavia.