Bach Inverted is a composition study in which the Well Tempered Preludes and Fugues of J.S.Bach – the “Forty-Eight” – have been re-imagined in their opposite (or inverted) mode.

Bach’s concept was to write a prelude and fugue in each of the 12 major and 12 minor keys. And so, from the 24 individual keys was produced 48 distinct works. These were completed in 1722.

Twenty years later, Bach repeated the process with Volume II. So now there are 96 exquisite works.

Bach Inverted takes each of the 96 works and re-arranges them in their opposite mode. That which was major is now minor, and vice versa. Strict rules were enforced, notably that all note names be respected while permitting alterations (flat, sharp, double flat, double sharp, natural). No notes were omitted nor added.


Emerging in the late Baroque period is a general understanding and exploration of modulation within the diatonic key system. With the advances in tuning systems, including the “Well-Tempered system”, it became theoretically possible to modulate to any other key and remain in tune on a keyboard. One can imagine the exhilarating effect this might have on composers who are craving advancement in their art. In the original Bach, one can see that not only were all keys explored one after the other, but modulations to new regions were also made possible. In the later volume, there is an increasing interest in chromatic movement, enabling more ambitious modulations but also exploring the limits of diatonicism in diatonic instability becomes a type of variation, while always returning solidly to the tonic.

Altering Bach: WHY DO IT??

It was a personal goal to come to terms with Bach’s rich harmony and technically bewildering counterpoint. The conversion of major to minor, and minor to major brought up many interesting challenges. The works ought to be viewed in the same way we view variation technique. 

The results are generally satisfying, although there are a couple that don’t really succeed. Major to Minor generally works better than Minor to Major. This is largely due to the expanded benefits of the minor scale offering 9 notes as opposed to Major’s 7, while Minor to Major obviously loses those possibilities.

The Preludes are generally easier, while the fugues, being highly structured and tending towards an advanced exploration of modulating diatonicism, are sometimes complex and difficult.

The resultant harmonic language could often be disguised as authentically Baroque whereas occasionally there are 20th/21st Century resonances. Some of the solutions could be considered contentious, thus inviting alternative versions from anyone so moved.

The ninety-six part cycle was completed in 2016. It was then fully revised in 2020 with its 3rd Edition.

The complete scores (keyboard style) can be found on the Australian Music Centre’s website here.

Below is the first page of Prelude Nº1 from Volume 1, now in C minor.

BI-WTC 1-01 Prelude