Is it emotion? If so, what about a singer’s performance evokes emotion?
Can it be feats of strength? Sensitivity? Fascinating ebb and flow of the lyric?
Are exciting singers “loud”? Can soft singing be exciting?
Can a voice be beautiful but not exciting? Exciting but ugly?
How about authenticity? Does it sound like we are hearing a real person?
Can the excitement of hearing a voice be ruined or enhanced by the appearance of the performance?
How can one person be moved and another unaffected by the same thing?
Some of these have easy answers, and some are almost impossible to answer. But we must ask all of these and more.