In 1972, the band Deep Purple played so loud, 3 people fainted.

Deep Purple is an English rock group formed in 1968. During a 1972 concert at the London Rainbow Theatre, the band played so loud, their sound reached 117 decibels. That’s about how loud the noise an entire football stadium is. As a result of the noise, three people reportedly fell unconscious. Deep Purple's members have changed many times since its beginning, and now consists of Ian Paice, Ian Gillan, Roger Glover, Steve Morse, and Don Airey.
The current record for decibels from a band is 139 dB, by Manowar. However, this was done during rehearsal and not the actual concert. The in-concert record goes to KISS, who reached 136dB in their concert. They were forced to turn the volume down
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