In 1958 Olga Iglesias made her debut in the second season of the Puerto Rico Casals Festival in Ponce, Puerto Rico under the direction of Richard Burgin, associate conductor of the Boston Symphony Orchestra. This was the first of multiple performances over decades in which Olga would sing as a participant of the Casals Festival. In July of 1960, Olga received a letter by renowned violinist and conductor Alexander Schneider, who at the time also held an administrative role for the Casals Festival. Schneider indicated that Pablo Casals had selected her to be the soloist in three concerts Casals was conducting in March of 1961. It was in these performances where she sang Donizetti’s “Regnava nel silenzio” from Lucia de Lammermoor and W.A. Mozart’s “No, no che non sei capace” from K. 419. In 1963, under Pablo Casals’ baton, she later went on to Carnegie Hall under the Casals Festival to sing in J.S. Bach’s St. Matthew’s Passion and in 1964 to sing in Haydn’s The Creation. These are two of three performances she sung at Carnegie Hall, in addition to many others under the baton of Pablo Casals and at the Puerto Rico Casals Festival.