Thus far, metal has remained largely immune to Auto-Tune, the insidious technology that does what this poster says. Auto-Tune is now standard equipment in just about every recording studio. In brief, it is used to turn an off-key note into an in-tune note. As a result, the bands and singers who use Auto-Tune on their recordings sound nothing like they do in live performances… unless they mime their singing to an Auto-Tuned track.
There have been accusations — or maybe they’re just unfounded suspicions — that a couple of metal bands have used the technology to make their albums sound better. That could be very risky since metal fans who know anything about Auto-Tune are united in their hatred of it.