Rocks in the head- Cantata for the fourth Sunday of Advent, Bereitet die Wege, bereitet die Bahn!

“And what do you do?” Apparently it's the question the Queen tends to ask her nervous subjects when opening the latest motorway flyover or widget factory. Everyone's heard it at a party- a safe way to cut through the conversational permafrost that builds up if the host has been too stingy with the gin. I'm a troublesome sort of sociopath, and I like to answer along the lines of “I eat, I walk around, I sometimes talk to people...”. Just watch their faces as they put you down in the Clearly Mad category. But it is quite ridiculous to equate what someone does for most of their life with who they are. Otherwise parties would be full of people saying “Oh! You sleep too! I do quite a lot of that myself- I'm hoping to turn professional...”

All this is a roundabout way of getting to the theme of this week's cantata. We need to clear some rocks from our mental pathways to answer the most crucial question of our life- “Who are you?”(closely followed by “What are you doing here?” and “Where is this bloody bus anyway?”). Unusually, we're plunged right into an aria from the beginning; a clarion soprano tells us to “clear the road, clear the way!”. The command is backed up by swinging orchestral ritornelli. It must have got the court of Weimar tapping their silver-buckled shoes- rather like Charles II of England, who could never abide music which he couldn't tap his foot to. The oboe struts its stuff, and the scoring gets richer and more complex until the line “Messias kömmt an”- the Anointed One comes. Suddenly, all the orchestra falls away to leave the soloist hanging in the air like a herald at a ballroom- which suddenly falls silent at the arrival of a scandalous guest. But the shock doesn't last long, and with a flourish the aria returns to the beginning and the dance begins again.

So far, so Advent- it all fits with the Old Testament command to prepare the way of the Lord, make his path straight, look busy etc. But here it's given a new twist. Rather than a social revolution, the call is to an internal turn-around and spring-clean. It chimes in with the themes of Pietism- roughly speaking, a movement that was present in the German states towards deeper spiritual devotion and mysticism and away from rationalism. Bach's librettist for this cantata, Salomon Franck, certainly had pietist tendencies; lines like “Machet die Stege im Glauben und Leben dem Höchsten ganz eben”- “make the flagstones in your faith and life completely even” certainly fit in with this focus on inward reform.

But Pietism wasn't just about ignoring the world in favour of achieving internal spiritual ecstasies. In fact, in Bach's time Pietists founded hospitals and orphanages across Germany. And the cantata sternly declaims in the tenor recitative that follows:

So müssen Herz und Mund den Heiland frei bekennen.

Ja, Mensch, dein ganzes Leben

Muß von dem Glauben Zeugnis geben!

(“So must heart and mouth freely acknowledge the Saviour; yes, O Man, your whole live must give witness to your faith!”.) And when he calls on us to roll away the “schweren Sündensteine”- the heavy stones of sin- then we can hear in the lumbering, rolling bass line quite how heavy and resistant to being pushed around these spiritual boulders are.

And it's a theme that Bach returned to exactly a year later, in 1716. In the opening chorus of his cantata BWV 147- again written for the fourth Sunday of Advent at Weimar- he set the very similar words:

“Herz und Mund und Tat und Leben

Muß von Christo Zeugnis geben”

(“Heart and mouth and deed and life

must give witness to Christ”.)

So clearly we're dealing with a subject that resonated with Bach- the total integration of human existence, with one purpose alone and one identity as a Christian. And that theme of integration and identity leads us straight into the bass aria. “Wer bist du?”, it starts. Who are you, indeed? As a whole, how does your life show the identity you want? But this isn't a journey towards self-discovery in a fluffy, going-to-Thailand-on-a-gap-year sense. For Bach and his librettist, the process is a shocking and saddening one. There's a wonderful harmonic sag on the words “Ein Kind des Zorns in Satans Netze” -a child of wrath, in Satan's nets”. It feels like the stone tower of self-regard that sustains us is starting to collapse.

And it won't do you any good to point to what good Lutherans you are, warns the alto recitative that follows.  We know that on that particular Sunday, Bach's congregation would have heard a portion of the story of John the Baptist earlier in the service; and the resonance with this section is clear. Just as John the Baptist called the Pharisees (who had rather pompously pointed out that they happened to be descended from Abraham) a nest of vipers, the alto recitative gives a picture of baptism as a Taufbund- a baptismal contract- where the recipients have failed to live up to their side of the bargain. It's not comfortable listening- indeed, a strict rationalist Lutheran of the time might say that it verges on heresy. But Bach pushes us to the edge of despair in order to show the depth of redemption

The only path left is for the soloist, once again, to sing Erbarme dich- have mercy- in a tiny prefiguring of the great desolate alto aria of the St Matthew Passion. And then at last the hope arrives- the violin melody flows over the top of the final redemptive aria like an endless stream of cleansing water.

We're left with the strange and disturbing request in the final chorale: “Ertöt uns durch deine Güte, Erweck uns durch deine Gnad!”. "Slay us in your goodness, wake us through your grace”. The demolition of all the stones of the old person might seem like a death. But only once all that rubble has been cleared from the soul's path, can we give a true answer to the question at the heart of the cantata and of all of us: “Who are you?”.