Adagio in G minor for strings and organ, also known as Adagio in Sol minore per archi e organo su due spunti tematici e su un basso numerato di Tomaso Albinoni (Mi 26), is a neo-Baroque composition commonly attributed to the 18th-century Venetian master Tomaso Albinoni, but actually composed by 20th-century musicologist and Albinoni biographer Remo Giazotto, purportedly based on the discovery of a manuscript fragment by Albinoni.
There is continuing scholarly debate about whether the alleged fragment was real or a musical hoax perpetrated by Giazotto, but there is no doubt about Giazotto's authorship of the remainder of the work.
According to Giazotto, he obtained the document shortly after the end of World War II from the Saxon State Library in Dresden which had preserved most of its collection, although its buildings were destroyed in the bombing raids of February and March 1945 by the British and American Air Forces. Giazotto concluded that the manuscript fragment was a portion of a church sonata (sonata da chiesa, one of two standard forms of the trio sonata) in G minor composed by Albinoni, possibly as part of his Op. 4 set, around 1708.
In his account, Giazotto then constructed the balance of the complete single-movement work based on this fragmentary theme. He copyrighted it and published it in 1958 under a title which, translated into English, reads "Adagio in G minor for strings and organ, on two thematic ideas and on a figured bass by Tomaso Albinoni".
Giazotto never produced the manuscript fragment, and no official record has been found of its presence in the collection of the Saxon State Library.