Yes, this is the opera that Johann Sebastian Bach never wrote. Six cantatas staged in a huge doll’s house of a set, as a sort of community Everyman morality play. Actus tragicus was the director Herbert Wernicke’s artistic last will and testament: it was premiered in Basel in 2000 and Wernicke died two years later. The Stuttgart Staatsoper adopted the show in 2006 and have just brought it to Edinburgh, playing to packed houses.

The tragic act of the title is that of life itself. Vanity of vanities, saith the preacher — and the production. In each “room” of the set the stuff of life goes on as a moto perpetuo, reproached by the Lutheran doom and gloom of Bach’s darkest, most death-obsessed cantatas. Those who sing them, be they chorus or soloists, are at work, ironing, taking out the rubbish, celebrating Christmas, hanging themselves, making love.

As a counterpoint to these mundane preoccupations is a gentle undertow — a dream-play, if you like — of those whom we have always with us: the postman, the religious obsessive, the man who measures, the man who needs to know the time — even a Strindbergian window cleaner. Like the singers themselves, each is doing his or her thing, yet each is an inextricable part of the mortal mass.

As such, Wernicke’s staging is a moving soulmate for Bach’s music. And the variants within the ever-repeating actions are clever and true. A football rolls across the stage at the silent start of the show and is later retrieved by an eloquent boy treble; when the woman who is breaking her back taking out the bulging sacks of rubbish meets the beggar on the stairs, who is more to be pitied? But, like the humanity it celebrates and laments, Wernicke’s concept is flawed. It is undermined by figures that verge on the unintentionally and unironically risible, such as the black-clad figure of Death, with white mask and white gloves, and the embalmed body of the prostrate Christ below.

This, alas, is every bit as heavy-handed as the musical performance. Michael Hofstetter conducts an orchestra that chunters on metronomically, like 1960s German Bach at its worst. And, while an opera company may well not be used to singing Bach, the ear, tuned to any number of fine festival performances, rebels at what is often crude and unstylish singing. The spirit is willing, but the flesh is weak. And that, I suppose, is exactly what it is really all about.