Sorry, there are no upcoming festivals in Bristol.
In the early 1980s, Bristol was characterized by its underground scene, focused on graffiti (with the likes of Banksy!) and music. The period focused on political activism and multiculturalism. This period brought about the music genre that Bristol is very specifically known for: 'trip-hop,' an intense fusion between hip hop and electronic music.
In terms of festivals, Bristol is best known for its In:Motion series.