This unique volume brings together side by side the two distinct versions of Vivaldi’s unusually titled concerto Il Proteo ò il mondo al rovverscio (“Proteus, or The World Turned Upside-Down”), both dating probably from the mid-1720s. Not only are we able to glimpse the fascinating creative process involved in the conversion of one concerto into the other, but the two works are differently scored, providing equally valid alternatives for performance.