Polca d'Ours
Polca d'ours, known in the UK as "Bear Dance" is usually played at the end of a castells performance, for a particular dance (see first video). Normally you play it three times, starting slowly and getting faster each time.
There is some debate about whether it should be played in a performance, since it is not considered a traditional Catalan tune. It is played across Europe, from UK to Italy, and I do not know the origin.
