For the recovered sheet music co-written by Mozart and Salieri

Unbelievable. This year, in January, they discovered a piece of music that was lost for centuries - and co-written by Mozart and Salieri. It's called For the recovered health of Ophelia.

This recording seems to suggest that the piece is just three small pieces strung together, the first written by Salieri, the second by Mozart and the third by Cornetti. Nobody knows who the hell Cornetti was. But I haven't found anything written about this piece yet explaining how they know who wrote what.