Underpinning so much of Sir John Eliot Gardiner’s approach to Bach is identifying the provenance and essence of dramatic character, ‘mutant opera’ (as Gardiner calls it) found in genres – like the motet – which are not enacted but depend on perceptive rhetorical judgement within a fabric of rolling continuity. Bach’s motets may pay homage to forebears in scale, tone and technique but each one, especially revealed in this vibrant and questing new set, presses for fresh meaning with all the virtuoso means Bach could muster.

The motets have appeared as pillars of the Monteverdi Choir’s existence over five decades, punctuated by a notable recording for Erato in the early 1980s and most recently within selected programmes during the millennial Cantata Pilgrimage. For Gardiner, these works represent an endlessly fascinating tapestry of discovery which will doubtless continue to evolve, a body enhanced by the addition of Ich lasse dich nicht – a short motet once thought to have been by Bach’s great elder cousin, Johann Christoph, but now considered the work of the Young Turk.

Common to the Monteverdi Choir’s performances over the years are their inimitable textual projection, clarity of line, rhythmic rigour and an overriding sense of expectancy and flair, just occasionally slipping a little too eagerly into exaggerated gesture. Gardiner asks for more pinpoint delicacy, quicksilver contrast and lightness than ever and illuminatingly inward da camera dialoguing between voices. For all the pages of sprung bravura and purpose, especially in Lobet den Herrn and Singet dem Herrn, there are as many periods of elongated and poignant restraint.

There is no more compelling example than the soft, controlled climate of the final contemplative strains of Fürchte dich nicht, where we have an extraordinary representation of the precious mystery of belonging to Christ. The soprano motif on ‘und dein Blut, mir zugut’ (‘thy life and thy blood’) is uttered with such sustained and ritualised other-worldliness (track 15, 5'38") that the risk of disembodiment is only allayed by the Monteverdi Choir’s captivating certainty of line as the devoted soul drifts heavenwards.

One of the most striking features in this new collection, as I mentioned previously, is how attentive Gardiner is to the individuality of each of the motets. This might seem a time-honoured ambition and yet, for all the admirable qualities of, say, the RIAS Kammerchor under René Jacobs or the more recent reading from Philippe Herreweghe and Collegium Vocale Gent, neither of these brings as ambitious a kaleidoscopic challenge to the listener in identifying renewed character and meaning as Gardiner aspires to. Indeed, Herreweghe recently went as far as to say that ‘a groundbreaking reading is not necessary’.

Gardiner would disagree. How lucidly Der Geist hilft (that short but compact work written for the funeral of Ernesti, the old Rector of St Thomas’s, in 1729) sets out to reflect the infirmities of man gradually imbued with the intercessions of the Holy Spirit. Here we have something more perspicacious than merely good pacing: the Monteverdi singers narrate this play of uncertainty and the growing anticipation of understanding God’s will with such corporate and dynamic purpose that, even when the two choirs converge in an affirming four-part double fugue, we never feel quite out of the woods. The tantalising prospect of salvation is only truly satisfied at the final cadence of a luminously directed chorale.

Some of these interpretative risks may not suit those who prefer a less articulated, more abstract, soft-edged and generally expansive landscape. Singet dem Herrn is typically exuberant in its outer ‘concerti’ but the unique double-choir juxtaposition of chorale and free contrapuntal ‘rhapsody’ could perhaps have yielded more genuine contemplative warmth. Indeed, Gardiner rarely delivers a comfortable ride and yet what brilliant visions emerge, most strikingly in the central work, the five-part Jesu meine Freude, riding – literally – the storm of the love of the flesh, Satan, the old dragon and death.

Throughout this masterpiece, terrifying, quasi-‘turba’ (crowd) scenes are viscerally offset against an ethereal quest for redemption. ‘Es ist nun nichts Verdammliches’ (‘There is now no condemnation’) has surely never enjoyed such a mesmerising volley of declamation and rich illusion over a short space as Gardiner summons, while ‘Trotz dem alten Drachen’ (‘Despite the old dragon’) spits out its irascible consonances only to be disarmingly defied by the elevated purity of ‘in gar sichrer Ruh’ (‘in confident tranquillity’) – all this in contrasting tableaux of ever-surprising emotional impact. If the listener is often left gasping, this is caused not only by vocal singularity of purpose but by the discreet and graphic responsiveness of the instrumental continuo players, among whom the bassoon here (and in Komm, Jesu, komm) contributes with knowing effect.

As you would imagine, surprises abound – some of which take a little getting used to. Gardiner challenges orthodoxy in how these a cappella holy grails are fundamentally signposted and he does so, almost always, with persuasive passion and genuine zeal. High-wire artist Philippe Petit is a fitting cover image to this important landmark in highly recommended, high-stakes performances.