Reger’s Op 110 motets belong to a select group of a cappella works (Friede auf Erden, Figure humaine, Jolivet’s Epithalamium and Strauss’s Deutsche Motette) whose prodigious challenges place them out of reach of all but the most proficient vocal ensembles. However, as the list above should indicate, the effort taken both to master them and pay them attention brings commensurate rewards. In the descending chromatic gloom which opens No 1, ‘Mein Odem ist schwach’, Brahms’s own trio of Op 110 motets meet their Götterdämmerung.

The four-movement structure mirrors Job rousing himself from despair to hope. A fugue for his ‘heedlessly wrangling’ comforters is brought to a dramatic standstill by a chorale, which in turn cedes to a patiently contrapuntal setting of ‘I know that my Redeemer liveth’: intricate but not a bar too long, at least not in these superbly assured performances by the SWR Vokalensemble. Doubtless the fugues (one of hair-raising length and complexity closes the second motet) are instrumentally conceived but the singers betray no lack of sympathy or stamina.

Without pushing on the tempo or whipping up fake pathos, Frieder Bernius extracts every last drop of juice from Reger’s word-setting. Just a little air between the notes for ‘My days are cut off’ makes all the difference to both texture and sense, where a previous recording under Hans-Christoph Rademann (also on Carus) takes the phrase in one legato breath. That was with the larger NDR Chorus, who more nearly approach the forces Reger had in mind, but sheer volume is a sacrifice worth making for choral singing that finds the centre and stays there. The slow movement of the second cantata is a hymn to rest in time of trouble: simple, humble and heart-stoppingly lovely. Written by an English or American composer, it would gain the same airplay as Lauridsen and Pärt.

A brief but helpful booklet-note in the CPO disc of chorale cantatas suggests that Auferstanden, Auferstanden is unfinished because the composer ‘had lost interest in writing such deliberately simple music’. It does not make a promising start to the disc. Placed second is the masterpiece of the set, O Haupt voll Blut und Wunden for Good Friday, but the Carus performance is immediately preferable. Both pitch and overall presence are more clearly focused, the obbligato oboe and violin lines are wrapped sinuously around the homophonic chorale harmonisations, the brief vocal solos are more assured and Bernius projects a sense that the piece matters to him.

The remaining chorale cantatas also unite the full musical resources of a church (congregation, young choir, organist and talented instrumentalists) in presenting long chorale texts with ingenious variety if not consistent inspiration. For those who associate Reger with brain-melting contrapuntal intricacy, the disc will come as a surprise, and maybe a pleasant one: spring water after the single malt of the Op 110 motets.