I have always stated that there are reasons why singers become famous and vocal skill is not the primary reason, but it must play a part. Whether it is Dolora Zajick's carefully-crafted impersonations of Verdi's "Witches and Bitches" as the great mezzo roles are often referred to, or Bryn Terfel's singular charm or Jonas' Kaufmann and Anja Harteros' "südländische" good looks (as they play so well in the North), each singer who comes to stardom have something that sells beautifully on billboards and Youtube trailers. The glimpse you get from these people in costume is defining. But can they sing?
The acoustics tell us a resounding "YES"! As it relates to acoustic balance, most of the top singers with rare exception exhibit that illusive chiaroscuro balance between appropriate low and high overtones. Whether by natural coordination (unconsciously learned balance) or conscious training, the top singers indeed have the stuff of operatic gold. Then what is the problem?