This is a little bit long winded but bear with me!
A few years back, playing in a punk/ska band at the time, we played at a bar in Luton after an England football match. Anyone in the UK should know of Luton's reputation, but for those of you that don't, it was voted England's crappest town a few years back. Really not a very nice place.
Anyway, we turn up, the place is packed with rowdy football (soccer for you Americans

) fans who've been on the beers all day, maybe 150-200 people or so. Soundcheck has to be done in front of everyone there. We see the other bands soundcheck, then promptly get majorly heckled when each of them finishes. At this point we're all slightly worried, as it seems live music isn't something they are particularly interested in hearing. Then its our turn. Our 2 guitarist/vocalists who are a bit more into the football world than I am, sense the predicament and try to get everyone on our side by singing some Luton football chants while we soundcheck. This gets the whole place singing along. After soundcheck, a rather large skinhead bloke from a table of about 10 other equally large skinhead blokes right in front of the stage (I say stage, it was ground level with a few monitors marking the front of it) walks up to one of the guitarists and introduces himself with this line: "We're football hooligans and I'm the leader of this bunch. What team do you support?". At which point guitarist nervously answers "Arsenal/ Luton". The large blokes face lights up a bit, he turns around and lifts up his shirt to reveal a huge Arsenal tattoo on his back. Turns back around and says to guitarist "don't worry about a thing, you boys are invincible while we're around". Few hours later, we play our set, with these 'football hooligans' dancing around, more football chanting, and the police outside telling the promoter to calm things down, something about inciting a riot. The football chants seemed to get everyone in the place into it.
That was the only time I've ever turned up for a gig and genuinely not wanted to play it out of fear. Turned out to have some of the most fun i've had gigging. Very lucky I suppose to have a couple of guys in the band who were more capable of dealing with things than I was. The football connection saved the day!
Sorry that went on a bit, I tried to sum it up the best I could!