he said that he studied one year at Austria close door full time. No languages of any of the opera world, memorized and fully mastered 12 operas, had the scholarship to have all kinds of coaches and teachers coming in all day for classes...
@Mirjam de Vries doesn't have to be written to be expected... the B natural in La Donna è Mobile is also not written by verdi on score. Yet imagine how sad would be to finish that aria in a B3 (as written). In opera there's tradition... and tradition sometimes beats the score.