Wilson Pereira wrote:

>Alan Moss wrote, replying to Walter Meyer:
>
>And, one might add, hardly needs enhancement through acting.  Caruso once
>famously remarked that all one needed for a good performance of "Trovatore"
>were the four greatest singers in the world.
>
>I thought this was a quotation from Toscanini...

According to Ethan Mordden's *A Guide to Opera Recordings* (p.  126), the
statement was Caruso's.

Walter Meyer