Sor’s fantasia op. 30 consists in fact of two sets of variations. The work was first published in Paris in 1828 and dedicated to Sor’s colleague Dionisio Aguado. The variations were played by Sor in a concert of his in Paris (see my book Fernando Sor, Composer and Guitarist, chapter 5). The original title was 7e. Fantaisie et Variations Brillantes sur deux Airs Favoris connus (Seventh Fantasia and brilliant variations on two well-known airs). The theme of the first set has been identified as the French folksong “La mère Michel”.
This edition comes from the new 2019 second edition of Sor’s New Complete Works for Guitar edited by Brian Jeffery. The Introduction and Index to the entire series can be seen here on this site.