This is soprano in the modern sense, i.e. upper female voices. Separate files are included for soprano 1 (always the highest part) and soprano 2, which is the middle part when the split is into three, top part otherwise. There are no four-part splits. Act 3 is never in more than 2 part so there is only one file for that act.
This recording was prepared using the Ricordi/University of Chicago Press critical edition of 1996. There may be one or two small differences from other, older editions.