Invention No. 6 in E Major, BWV 777 (page 22)

This is the same music as presented in the solo version, but here arranged as a duet for two pianos. As in several of the other duets, Piano 1 has the easier task of presenting only one line.

Prelude No. 9 in E Major, WTC I, BWV 854 (pages 24 and 26)

Two duets (at least!) are possible with the Prelude in E Major, WTC I, one with an added line and one with a chorale accompaniment. The added line is intended to be played on a second piano, the concept behind all the duets in this volume, although the register of the added line would permit realization by other instruments such as the flute. The chorale accompaniment shows the underlying harmonic scheme of the piece and, since it is laid out in a strict SATB format, could conceivably be sung by a choir, instead of played by a second keyboardist, while an organist plays the prelude. Yet another possibility would have the organist playing the prelude, the choir singing the chorale accompaniment, and a flutist simultaneously playing the added line.

Prelude in D Minor, BWV 926 (page 28)

Unlike some of the duets in this collection, here Piano 1 is not necessarily easier than the original Bach Prelude (Piano 2) it adorns. The 16th-note scale passages are to be played with razor-sharp clarity and end up sounding like the protagonist within an accompanimental context created by Piano 2.

Fugue in Ab Major, WTC I, BWV 862 (page 30)

Like the chorale accompaniment to the Prelude in E Major, the chorale accompaniment to the Fugue in A Major could be played on a keyboard, sung by a choir, or played by a string quartet. A largely homophonic and static texture of the new part prevails in measures 1-17 while polyphony and activity come to the surface in measures 18-35. The accompanimental function of the added section in the first half converts to a more leading role in bars 24-27, when the newly created top line of Piano 1 creates a “duet” with the tenor voice of Bach’s fugue (Piano 2).

Invention No. 13 in A Minor, BWV 784 (page 34)

An already energetic piece becomes even more intense with the addition of 32-note lines, justifying possible nicknames such as “Busy Bee” or “Angry Flutist.” The most interesting harmonic twist probably occurs at the end of measure 16, where the added line’s ascending E melodic minor scale, starting on C#, concludes with a Dn on the downbeat of measure 17.

Invention No. 8 in F Major, BWV 779 (page 37)

The added continuo part presumes that the Invention has the character or Affekt of a bright concerto grosso, such as the first movement of the Brandenburg Concerto No. 2 in F Major, BWV 1047. The Invention in F Major could have been easily transformed into the larger orchestration, with incisive, clarion sonorities.

Invention No. 14 in Bb Major, BWV 785 (page 40)

This arrangement was first published in the fall 2001 issue of the magazine Piano Today. The second treble line was conceived as if the Invention were a trio sonata, even though the register transcends any traditional trio-sonata instrument. The added melody creates a texture somewhere between a trio sonata and a Sinfonia (three-part invention). Measures 17-18 continue Bach’s stretto in the added line, a contrapuntal technique that makes the work sound more like a Sinfonia, with three independent voices manipulating the subject. Despite the intellectual rigor suggested by these polyphonic tricks, the predominant mood or style is pastoral, reminiscent of the aria “Sheep May Safely Graze” from the Hunting Cantata, BWV 208.

“Bachy Boogie” on Invention No. 14 in Bb Major, BWV 785 (page 42)

As the only example in this volume conceived outside Bach’s style, “Bachy Boogie” may raise issues of good taste and the role of the performer. For some pianists, such a transcendence of 18th-century style may seem a perversion of historically informed performance. But in the context of Bach’s own wide absorption of French, Italian, and German genres and idioms, the amalgamation of musical languages in “Bachy Boogie” continues a time-honored tradition. The tempo for this duet version of Invention No. 14 will probably be brisker than the other, more pastoral setting of the same invention; articulations will also more likely be punchier and accents a bit more unpredictable.

Prelude No. 1 in C Major, WTC I, BWV 846 (page 45)

Admittedly, Charles Gounod probably paved the way for the present version with his 1853 “Ave Maria” addition to the Prelude in C Major, WTC I. His longer note values suggest a vocal realization, whereas the added line here has more notes, perhaps more appropriately played on an instrument.

Prelude No. 5 in D Major, WTC I, BWV 850 (page 48)

Like the duet version of Prelude No. 1 in C Major, WTC I, this duet can be played on another keyboard or by an instrumentalist. The rather confined range of the added line would work equally well on a violin, oboe, alto saxophone, or other instrument. The concluding measures of Bach’s original prelude were expanded here to allow more cadenza-like liberty for the added line.