In his later years Beethoven, like many other composers, turned to the music of J. S. Bach for new ideas. However, Beethoven's admiration of the late Baroque master began while he was still in Bonn. Possibly as an homage to Bach's preludes and fugues in every key, Beethoven composed two Preludes, both employing each of the 12 major keys. These are less successful works than his later contrapuntal masterpieces, such as the Piano Sonata No. 28, Op. 101, the first movement of the String Quartet, Op. 131, and the Grosse Fuge, Op. 133. It is possible that Beethoven wrote the Preludes, Op. 39, as composition exercises for his teacher, Christian Gottlob Neefe (1748-1798). The Preludes were published in 1803 by Hoffmeister and Kühnel in Leipzig.
Each Prelude opens in C major and travels around the circle of fifths in the "sharp" direction -- C to G to D, etc. -- and end up back at C major. The Baroque conception of the pieces is most evident in the linear writing, with independent inner voices.
The first Prelude of the pair is in common time and opens with the theme in the right hand, imitated a measure later in the left. The imitation ceases, however, after only two measures. The piece is generally in three voices with moments of four-voice texture, notably in the C sharp major segment, which for a moment abandons the eighth note pulse. The tune of the very first measure remains consistent throughout the Prelude, appearing at every change of key and for long stretches in every measure. Beethoven stresses the descending four sixteenth notes of the theme in the sections in E flat and B flat, counterbalancing these with upward motion in the F major passage before returning to the theme in full to close in C major.
Cast in cut time, the second Prelude features a quarter-note rhythm almost exclusively. The theme, only four measures long, has fewer landmarks than the theme of the first Prelude, and the music seems to meander from key to key. The texture is consistently dense except in a few places, such as the beginning of the E major passage, which opens with one line in the left hand only. Several keys -- D, A, F sharp and E flat -- appear for only one measure each. Once Beethoven reaches C major and a nearly literal repeat of the opening measures, he begins the process again, this time allotting only one measure to each of the key areas.