The Obertura de Concierto (1920) was Rolón´s first concluded orchestral composition. Julián Carrillo premiered it at the Teatro Arbeu in Mexico City in April 1921, further performances are unknown. Today exists only a set of orchestral parts by the authors hand, the score is lost. These parts show certain marks and corrections by different hands, probably by the musicians who used them. Nevertheless, the string parts have not been used, Only one copy per instrument is left, without any corrections, bowings or fingerings. This set of parts dates from July 1920, as Rolón marked on the 1st violin and the oboe parts. Rolón sent the Overture at beginnings of 1920 to his former teacher in Paris, Marc Delmas, who commented it extensively in two letters, dated from 1st of May and 12th of July. Because of the date of the second letter, we don´t know whether the performing material what Cariillo used one year later is the same we have - the musician´s marks suggest that - or whether Rolón elobarated alter Delmas´ second letter a new, now lost material