Cognitive Daily explains Why we can’t all be divas. Rita Wolpert of Caldwell College separately recorded a singer and her accompaniment, then later processed the accompaniment so that it played a tone higher and mixed it with the original vocal track. She then played the synthesized recording for 40 nonmusicians and 10 professional musicians.
Only 5 of the “nonmusicians” — which actually included 7 people with over 6 years of musical training — could conclusively tell that two of the arrangements were sung in a different key from the accompaniment. Meanwhile, the musicians uniformly reacted with disgust, easily identifying the problem with the flawed arrangements.
While 42 percent of the nonmusicians did mention the key as potentially a problem, the remainder didn’t mention it at all, and none of the nonmusicians indicated that the bitonal arrangements were at all unpleasant.
So an aspect of music which musicians find critically important and (often painfully) obvious is simply unnoticed by most listeners.
One of many reasons that musicians don’t hang out at Karaoke bars.