At the age of twelve José Vianna da Motta wrote the Fantasia brillante on Carlos Gomes' opera "Il Guarany", op. 34 which is classed with his childhood works written between 1873 and 1883. Vianna da Motta had initially entitled this work Il Guarany, Grande Fantasia dramática de concerto op. 34 before giving it the title Il Guarany, Fantasia brilhante op. 34. We have chosen to follow the structure of the title as Vianna da Motta wrote it in the index-catalog of his music notebook: "Fantasia brilhante sobre o Guarany". The title of the work as it is presented in this edition is the result of an editorial choice aimed to standardize the titles in Vianna da Motta's catalog. It should be noted that the composer had initially referred to his work as "op. 34 n.º 1", which leads us to believe that he intended to include other fantasias inspired by operas in this opus.
With the exception of section A, in which variations are composed on the initial theme of the overture to the opera Il Guarany by Brazilian composer Antônio Carlos Gomes (see structural analysis below), Vianna da Motta essentially transcribes parts of this opera.