No score of the original Duo has survived - only the parts written in Sibelius’s own hand. On the back of the viola part the composer has written the date “1886?” Research has shown, however, that the year of composition was somewhat later, either 1891 or 1892. The violin part is easy and simple in character and the viola performs a strictly accompanimental role. It seems likely that Sibelius wrote this piece as an exercise for pedagogical purposes.