The Op.42 Notturno for Viola and Piano is an arrangement of the 1796-97 Serenade in D Op.8 arranged by F. X. Kleinheinz (with Beethoven's approval) for Viola and Piano. The piece is comprised of seven shortmovements. The first is a simple march while the second is an Adagio. The ensuing minuet is attractive and proves to be an interlude between two Adagios of which the second alternates effectively with a contrastingAllegro molto Scherzo section. There follows an attractive Polonaise and a theme-and-variations marked Andante. A reprise of the opening march concludes the work. Overall it is a delightful minor compositionin Beethoven's vast output.