In music production worldwide the 'Underground Techno' has a popularity that stretches its own definition, let along its style.
So, the answer to all these is co-existance and some people to stay true to their beliefs, keep Techno & Underground in perfect balance.
Then, the equation is legit.
Berlin is a city that had always been Techno, had always been Underground. Even when by the early nighties the rave scene became mainstream, Berliners went on seeking a darker, harder, industrial (that fits their environment better) scape. What they created they called it TEKKNO. And berlin stayed true to this character since.
This is a fact potrayed by Dj TANITH, his set was right to the core of Underground. Aimed precicely.
DJ Tanith is another one of the Berlin's founding techno fathers.
Tanith.org
DjTANITH
REPORT2DANCEFLOOR RADIO