I completely agree with Amber when she said that it is hard to determine the class of the individual people that make up the band when you don't know them personally. However, I will do my best to analyze and determine the class of Wedding Banned as a whole based on the information I know about them.
By simply observing them in person and viewing their webpages, I would immediately rule out the idea that they are upper class. They are an extremely laid back and care free band that just likes to make people laugh and have a good time. Basically the complete opposite definition of upper class society. Their audience very much reflects the band. While Wedding Banned is enjoyed by people of a variety of ages, the predominant age group is definitely the college crowd. We all know that most college students are not upper class. Also, the band performs at a very relaxed venue. The Copper Dragon, if you have ever been, is definitely not a higher class type of bar. It is an extremely laid back place where young college students come to have a good time and maybe get a little crazy. Which reminds me... the so called "weddings" they perform during their shows are definitely not upper class. If you are watching the show, the concept of a "white trash" wedding probably comes to mind. They pull up random people from the audience and embarrass them to death by making them do wacky things... often with inflatable dolls. Another concept that many people would view as white trash.
Overall, one can assume that the band is probably lower to middle class.