This recording was prepared using the Ricordi vocal score. There are known to be a few misprints in this edition, or at least discrepancies with the full orchestral score (which agrees more closely with the Schirmer vocal score). However, most of the differences are really minor. For instance, in act 2 at figure 20 Riccardo's part has C natural in the vocal score, C sharp in the orchestral. On this recording I play a C natural because, frankly, I prefer it.