On The Guardian's Comment Is Free, Sunny Hundal explains why some types of live music are being put under the cosh:
I was, until recently, a regular at a monthly club night before the police suddenly started strictly enforcing ID checks. This wasn't merely to ensure I was above the required 18 years of age. Not only was everyone required to provide visual identification, but they also had to be logged in a computer database – otherwise none of us could go in. Everyone's driving licences were scanned through a machine and recorded on a computer, with no indication of how long the police would store the information for.
When I objected, the (white) club promoter was quite frank with me. He said the police had said they were "concerned" that the venue played "black and Asian music" and hence wanted added security. Any sort of trouble is extremely rare at this night. Yet their reasoning was that if any fight broke out, they could track everyone at the event if necessary.
Form 696 explicitly singles out musical styles such as R&B, bashment, garage or styles including MCs/DJs as examples of genres that have to be stated if put on. It also required event producers to state the likely racial profile of people attending. When accusations of racial profiling were inevitably raised by the music industry, the Met changed the wording to ask who it was targeted at.