1. Everyone has a beard.
Not the women: There aren't any.
2. Everyone is nodding their head at different times.
Those that have managed to nod on the beat will have a smug look.
3. The flyer gives you no clue as to what the gig is.
"Post-hype intro jazz with textured soundscapes and lo-fi garage-core."
4. There are more wires on stage than in Maplin.
"You don't play your guitar through 23 pedals, a kaoss pad, an iPad and a nectarine?"
5. You are not allowed to dislike the music.
"You don't like it? You probably just don't get it because you're not a musician."
6. You are drinking a can of Red Stripe.
A strange anomaly of math venues.
7. You actually buy something from the merch table.
So you can wear an appropriate t-shirt to the next gig you go to.
8. The music confuses you.
If it just sounds like noise you assume that it must be in a time signature you don't understand.
9. You secretly love it when the music drops into a standard time signature.
"Yes! I can tap my foot without counting."