If you're outside Shinjuku station at the right time (maybe elsewhere also, but that's the station I used going to/from work), you'll see youngsters park up their vans, offload their gear and a petrol-fired generator, and play impromptu gigs full of energy, passion, urgency and noise, right there on the street.

Or at least you did when I was there 20-odd years ago. Mind-blowing.