In September 1728, Vivaldi met the Habsburg Emperor Charles VI in or near Trieste, where the emperor was supervising the construction of a new harbor. Charles was a great admirer of Vivaldi, and he gave him the title of knight and a golden chain with a medallion, and invited him to visit Vienna. In turn, Vivaldi gave the emperor a manuscript with a collection of concertos entitled 'La Cetra' (the cittern or lyre). It was probably no coincidence that the composer had used the same title for the Twelve Violin Concertos Opus 9 'La Cetra' featured on this CD, which he published a year earlier through Le Cène in Amsterdam, with a dedication to the Emperor. According to the Vivaldi scholar Michael Talbot, the lyre symbolized the great love of music of the Habsburgs. Earlier, in 1673, Giovanni Legrenzi had already dedicated an early anthology - likewise entitled La Cetra - to the-then Emperor Leopold I. Talbot also considers the use of scordatura (adjusted tuning of the strings) in the violin part of the 6th and 12th concertos of Opus 9 to be a homage to the Habsburg Emperor. The scordatura practice was indeed a popular tradition in Austria and Bohemia, as we know from the violin music of Biber and Schmelzer. Concerning the remarkable encounter between Emperor Charles and Vivaldi at Trieste in 1728, the Abbé Conti wrote: 'The Emperor talked about music at length with Vivaldi. It is said that he told him more in two weeks than his ministers in two years.'