Petersburg Cannons

How Bach Built A Canon

A practical hands-on lesson that delves into the mechanics of how J.S. Bach composed Invention no.1. BWV 772 which was written around 1720 to teach his young son Wilhelm Friedemann the basics of music. There is a Free download of the score arranged for two guitars, a backing track and analysis crib notes at the bottom of the page.

Okay so its not really about building armaments or even a Canon however it is about analysis and understanding the composers musical ideas and by extension his intentions; which is far more powerful. It also in honor of Bach’s 330 birthday which happens to be 31st of March.

What does all of this have to do with playing guitar? Well all the fine combing through the music allows you to approach phrasing and fingering a piece from a enlightened base. It also makes memorizing the piece, its structure and direction much easier as your knowledge is based upon the nuts and bolts of its construction. So grab a piece of manuscript or download the below blank manuscript idea with the cells already on top and lets getting building.

To start with if you are unfamiliar with this piece, take a listen here.

This piece can be boiled down to three original ideas, see below.


BWV 772

So………on your manuscript paper and before you read further, see how many ways you can manipulate, join or rewrite these three ideas to form some sort of six to eight bar phrase.

“Got it? Good!” Lets walk through some of the options that are available to you, and which Bach used. The first is the easiest and probably the one most of us did not consider to begin with.


Transposed cell

Transposed up a 5th

This is moving the notes up or down, as a unit i.e. keeping the intervals the same but onto different starting points or even into different keys.


BWV 772 Augmented Rhythms

Augmented Rhythms

This is keeping the idea and the intervals but lengthening the rhythms.


BWV 772 diminution

Lengthened Rhythms

This is the opposite of above, keeping the intervals but shortening the rhythms.

So………with all the above and still using those first three ideas, and your original ideas, write out another 8 bar phrase from fresh trying to combine all the new materials.

Ready for some more?

After all the above material we finally get to the most mystical manipulation methods available to composers. The next three are not as easily spotted but are utilised by Bach frequently. So without further fanfare let me introduce….


BWV 772 Retrograde

Retrograde Cell

This is the idea and intervals played backwards, simple as that.


BWV 772 Inverted

Inverted Cell

This is the idea and intervals played upside down.

Retrograde Inversion

BWV 772 Retrograde Inversion

Retrograde Inversion

This is the idea played backwards and upside down. If you compare with the above images you can get a good visual example of how the cell is moved around to achieve this.

So………this last time see if you can construct 12 bars of music with all you have learnt above, can you reverse Bach’s or even your own ideas? Below is a quick analysis of the first four bars of guitar one. Notice how Bach moves the materials forward instantly by transposing up a fifth and then cutting the material in half and inverting it. This is then transposed again; all in 4 bars.

Analysis of first 4 bars of BWV 772


Bach had an innate ability to manipulate music in this, and many other ways. One of which, canonic imitation is the simplest and also lent its name to this article. Once you play through the parts you will find it is also present in this piece, a lot. Download the score for two guitars, the crib notes and the backing tracking and get playing and analyzing; you after all have been invited to by Bach who prefaced this collection of lessons with:

“…those who are keen to learn are shown a clear to come by good ideas but also how to develop them well.”

Free Downloads Below


Crib Notes

Guitar Duo

Backing Track Download

The track has a five click start; a 4/4 bar and then beat 1 of the Invention. It has been split into stereo parts. The right hand is in the right channel and the left hand in the left channel. Just turn down the side you don’t need.

Back Track

Listen to the backing track here.


Classical guitarist who strives to share a little #6stringinspiration.

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