The critical edition of the Sei Concerti armonici by the 'amateur' musician Count Unico Wilhelm van Wassenaer (Twickel, [Delden, Holland] 1692-Den Haag, 1766) can be seen as the final stage of a long sequence of studies undertaken by the eminent Dutch musicologist Albert Dunning: studies that aimed first to identify the work's composer, then to consolidate its text by means of rigorous scholarly reconstruction. The enigma of the attribution of the Concertos dates back to 1740, when the editio princeps was printed. We finally end up with the name of Pergolesi, inscribed on an early 19th-century manuscript preserved in the Library of Congress of Washington. It is with this title and attribution, therefore, that the musicological and musical world became acquainted with the Concerti armonici, at least until the 1980s, when Albert Dunning unearthed a manuscript score of the Concertos, this time back in Holland in the castle of Twickel. The handwriting was indeed that of Unico Wilhelm van Wassenaer. The new critical edition of the Concerti armonici offers a text that comes closest to this 'newly discovered' composer's final conceptions. It thereby aims to disseminate some splendid works that even impressed a composer as distinguished as Stravinsky, who based the Tarantella of his "Pulcinella on the last movement of "Concerto armonico II.