It's probably that this drawing is a painting study (at Cau Ferrat Museum is conserved an oil 27 x 35 cm almost identical theme
-30674- ). It could be the definitive study of a painting presented at the Salon of Fine Arts in Paris in 1892 entitled Femme au piano (étude). This drawing illustrated an album that La Vanguardia gave its subscribers. At the complete catalogue of the works on display, "Pèl & Ploma", 10.28.1899, p. 3, indicated that the charcoal drawing "Miss. A...at the piano" was part of "a picture from the Casellas collection." At the photo of the Sala Pares published in Pèl & Ploma, 11.11.1899, 24, s/p. [p. 3] you can see this picture.
in pencil, a sheet says: Elisa, the sister of the artist