Thank you for adding some wisdom to this thread, Musicals 54.
Irra Petina created roles in the original Broadway productions of five musicals. One was a smash hit, one has become a recognized classic of the genre, and a third was a glorious "big sing" (though Petina didn't get the better numbers in it) that was just too old-fashioned for Broadway in 1965. Barbara Cook was in more Broadway musical flops than Petina was. And there was never anything wrong with Barbara Cook, either.