An Invention is a piece of music for the keyboard, usually written using two-part counterpoint.
Decided you want to learn the classical piano? Seriously? Then sooner or later you’re going to have to get yourself a copy of Bach’s Inventions. If you’ve already heard someone good play them, you may be rubbing your hands in eager anticipation.
Stick with them, and they should give you at least as much pleasure to play as to hear. But before that, the hand-rubbing may take on a rather different emotional complexion.
Bach’s two-part keyboard Inventions are probably the most beautiful and effective technical exercises ever compiled. But as with most exercise programmes, the early stages are likely to be gruelling and morale-draining. Take Invention No. 1, in the beginner-friendly key of C major.
For quite a lot of the piece the two hands are playing the same thing (more or less), only not at the same time. It’s as if the left hand’s starting pistol went off a bar (about two seconds) behind the right’s.
The beauty is that the two staggered parts not only fit together beautifully (like ‘Frère Jacques’ sung in imitation), they complement each other. As one descends, the other rises; as one lingers slightly, the other runs forward – a better demonstration of the principles of counterpoint is hard to imagine.
The trouble is, when you first try playing both hands together, you begin to feel that what you really need is two brains. It’s a bit like trying to pat your head while rubbing your stomach with alternate hands in contrary directions – only worse.
Persist, though, and the impossible happens: you progress from what psychologists call unconscious incompetence through conscious incompetence (so easy to despair at this point) to conscious competence, and finally (hallelujah!) to unconscious competence.
Brief pause for self-congratulation, then there’s the minor matter of the music, especially how to make this sound less like a machine and more like two voices in dialogue.
Of course if you go back further into the past, you can find pieces called ‘Invention’ that have no obvious didactic purpose – for example, Clément Janequin’s first book of madrigals (1555).
And in the 20th century, calling a piece ‘Invention’ can be more about demonstrating the composer’s prowess than inviting performers to develop theirs. But say ‘Inventions’ to trained pianists and Bach will spring to mind, perhaps with an accompaniment of knowing smiles.
After all, these are the ones who have endured the Dark Night and emerged to see the stars.
This article was first published in the November 2015 issue of BBC Music Magazine