Count Francesco Algarotti, a Venetian from a merchant family, was a model of an 18th-century cosmopolitan intellectual. From Italy he moved to Germany and established relations with various local princes and lords. During this period he had an epistolary relationship with Tartini. The musician composed music for sovereigns of the time and sent them through Algarotti, seeking favours for his students or an economic patronage for the printing of his writings. Tartini composed two groups of sonatas and concerts that he always delivered through Algarotti. In the first case we are dealing with “small sonatas” for solo violin and of concerts, intended for Frederick II of Prussia. We also have information regarding 6 violin concerts sent to Prince Ferdinand Philipp von Lobkowitz. Among the documents preserved in the Musical Archive of the Veneranda Arca del Santo in Padua is an autographed manuscript (I-Pca1888-1) which perhaps transmits the sonatas to which Tartini refers in the letter to Algarotti shown here. This manuscript includes late works conceived for solo violin and that is therefore played without accompaniment. Throughout his life Tartini was interested in popular music and many only partially identified melodies come from ethnic repertoires.