In the years since Moreschi last sang, recordings of arias composed for castrati, most of them written by Handel, have been transposed an octave for baritones or are sung by sopranos or countertenors.
When at long last some of them were revived in the 1920s, they were severely cut down and many of the lead parts, written for the star castrati of Handel's day, were transposed an octave down for a tenor or a baritone, leaving them barely recognisable.