There are stunning sopranos from Maria Callas, to many others too with unique voices to today as Montserrat Caballe for example, but with Yma Sumac the measuring stick broke, she was unique and incomparable, his record was inhuman, there is not precedent like her in past neither nowdays exist a person with that ability ringing voice ... so there are SOPRANOS and apart it is Yma Sumac.