Professor of Psychology Greta Munger and her spouse Dave write about the reactions of both judges and audience members of vocal talent shows such as American Idol.
The research they cite shows that judges, who are generally trained professional musicians, recognize notes in a song as being out of tune far more quickly and accurately than lay audience members. Munger wrote, "In other words, the singer was performing entirely the wrong note, but most listeners still thought it sounded fine."
The researchers called this propensity "the vocal generosity effect." The research also showed that listeners are more generous to singers than they are to other musicians, such as violin players.