you know those local orchestras? there is possibly some local people who sing well, along with a keyboard, a drummer and like a bulbul tarang or something?
those kinds of orchestras, every performer, including the vocalist demands for reverb on 11 from the sound engineer, the guy providing the speakers and doing the setup, which is referred to as a "DJ"
now 2003-2006 rock festivals started becoming a part of college festivals, as in many colleges started incorporating rock shows for the first time
the sound set up used for these rock festivals on those colleges, involved an engineer who came in and set up a sound according to orchestra, when the sound needed a rock setup
the festivals are two part, there are eliminations or auditions and the main show. this is the elimination stage, the band comes in, start performing, and the crowd and the artists have no clue why they are sounding like that. The engineer meanwhile, has abandoned his setup and has run to the speakers fearing for their lives, complaining that if music like this is played, his speakers will explode. So the DJs get an engineer, X who can set up the sound for rock.
The next year, when a different DJ is given the contract, he has the same problem again, and calls the previous one to ask for the setup. In another fest too, they call X for the set up.
Remember one of the finals of the fest involved, the professors came in and stopped the fest after the opening band played its first song, the guitarist for the headliners came on stage with his guitar and refused to allow the sound guy to remove one of his monitors and deliberately played a few solos to the audience just because he had come there to play and had been paid, while the vocalist gave a small talk directly to the audience about how heavy metal is also music, and that there is a technique to it, and that it is not just "noise"