When “The Voice” premiered in 2011, it distinguished itself from other televised singing contests by featuring a blind auditions phase. Contestants had 30 seconds to sing their hearts out while four rock-star judges sat with their backs turned to them. During that short 30-second interlude, each person had the opportunity to lure one or more judges to turn their chairs around based on voice only. Nothing else mattered.
The concept of the blind audition really came to the fore in the 1970s when major orchestras started to implement them.