Original manuscript sketchleaf in the hand of the important bel canto composer, showing an early stage of composition for the famous final aria from his opera Roberto Devereux, "Quel sangue versato." 19 single staves of musical sketches in several sections over two pages of a bifolium. The first four lines of music are a sketch of the melody of the aria, with the text: "Quel sangue versato in cielo s'innalza... Giustizia domanda, reclama vendetta... Già l'angiol di morte fremente v'incalza... Supplizio inaudito entrambi vi aspetta... Sì vil tradimento, delitto sì rio clemenza non merta, non merta pietà... Nell'ultimo istante volgetevi a Dio; ei solo perdono conceder potrà." The next three lines of music are without text; the final three lines of the section have some fragmentary lyrics below the music. At the foot of the first page, seven measures of music have been sketched out; on the verso, a further six lines of unidentified musical fragments. On manuscript paper with 16 staves per page; inner two pages of bifolium with blank staves. 29 x 22.5 cm. Some toning, edge wear and ink blots, but overall in fine condition.

The extremely difficult and virtuosic aria "Quel sangue versato" is sung by the character of Queen Elizabeth I in Donizetti's opera Roberto Devereux, when she learns that she has been too late to stop the execution of her beloved Robert. Haunted by his headless corpse, she sings that "The blood that has been shed now rises to the sky, demanding justice and revenge." The aria, which demands both strong low notes and powerful high notes as well as coloratura ornamentation, pushes romantic opera to the limits of melodic expression with its raw emotional content. The American soprano Beverly Sills was particularly known for her performance of the aria, although she commented that the difficulties of the role may have shortened her career by several years.

Born in Bergamo, Italy, Gaetano Donizetti studied music at Bergamo and Bologna, and produced his first opera in 1818 at Venice. The work which carried his fame beyond Italy was Anna Bolena (1830), and he had several other successes, notably Lucia di Lammermoor (1835). Sadly, after years of untreated syphilis, he became mentally ill at the height of his career and was institutionalized.