While Bach's D minor compositions can sometimes express sadness, this little prelude is also rather sentimental. Although there is no tempo marking, I believe it is appropriate to proceed slowly, like an allemande. In this prelude, the inner voice (alto) often appears in the right hand and is positioned quite close to the soprano; thus, an independent performance of both voices is desired.

For example, in the right hand during measures 7-8, the distinction between the soprano and alto is difficult, so please employ some device to make both voices distinctly audible.

The opening four measures are divided into two-measure phrases; in contrast to the theme in measures 1-2, measure 3 should be played quite sentimentally. From the third beat of measure 4, the theme shifts to A minor, so the atmosphere around this point should also be differentiated.

Furthermore, there are two versions of this score: one that ends with a Picardy third and one that does not. However, despite the frequent appearance of F-sharp in measure 9, it is highly unnatural for it not to end with a Picardy third. Therefore, in the final measure, measure 10, to ensure it ends with a Picardy third, I believe it is correct to play F as F-sharp.