Five star reviews are flowing Arcangelo’s way. It’s easy to see why. Five years after it was founded by Jonathan Cohen, the quality of this zestful ensemble just keeps soaring. Take their latest concert at St John’s Smith Square: three Bach Magnificats. Three? Surely JSB penned only one, sung in the traditional Latin of the main festivals (Christmas, Easter, Pentecost), and aired at that very first Yuletide – Leipzig, 1823.

But no, the other two were by other Bachs: JSB and his first wife Maria Barbara’s third son, Carl Philipp Emanuel, Telemann’s godson and successor at Hamburg (following a sojourn at Frederick the Great’s Potsdam); and male offspring number eleven - JSB and Anna Magdalena’s youngest, in fact: the ‘London Bach’. This was Johann Christian, who famously nurtured the eight-year-old Mozart when the latter (today commemorated by a boyish statue on Orange Square) was living on carriage-thoroughfare Ebury Street. JCB moved earth to inspire the pre-Idomeneo prodigy: a hefty piano concerto pioneer, as well as operatic innovator.

Cohen, by shrewd programming, was right in holding CPE back till last. The opening JCB Magnificat suggested a pithy but minor work, dated 1760, when he was 25, soaking in Italian influences (he was briefly organist of Milan Cathedral). It had massive punch, was a substantial chorus (though also solo) work, and a pretty joyous success: one would gladly have settled for a work double its length.

It offered a chance for ex-Regensburger Domchor chorister, the bass Thomas E. Bauer, whom I thought superb, to flourish. Cohen went for the gizzards of this driven work and caught, not so much the Italianateness (though that was there), as the work’s echt Germanic thrust. Scottish tenor Thomas Walker made a substantial impact: a natural Baroquist, learning from Cummings, McCreesh, Curnyn, René Jacobs: in short, a find.

So subtle is the orchestration of JSB’s Magnificat that others among Arcangelo’s ranks shone: cellist Luise Buchberger; Baroque double bassist Judith Evans; flutes Rachel Brown and Katy Bircher, like haunting recorders in Iestyn Davies’ Et esurientes; not to forget, from the back violins, Julia Kuhn and James Toll.

It was Dutch mezzo Olivia Vermeulen, another Jacobs protégé, who for my money made the running here (‘Et exultavit’). She has punch, character, and terrific presence. Davies’s duet with Walker, ‘Et misericordia’ felt paced to perfection, and exquisitely paired. Cohen fiddled with some gaps between movements: meaning to boost intensity, but at times plain clumsy. A few rhythms wobbled too.

But CPE won the day. Who, till recently, has noticed Der Auferstehung und Himmelfahrt JesuDie Letzen Leiden des Erlösers, or Die Israeliten in der Wüste? Nor yet his Markus- and Mätthaus-Passions? Till recently, you’d think CPE had never been mighty Hanseatic Hamburg’s leading light. So hurrah for Cohen’s Arcangelo that this Magnificat does get airings. Arguably it doesn’t show Philipp Emanuel’s full gifts of his last three decades. It part echoes the Pietist sentiments of some of his sire’s cantatas; sometimes – just a year before JSB’s death – there are even melodic relationships to his father’s Magnificat.

CPE’s Magnificat was actually a sneaky pitch for his father’s Kantor job at Leipzig. It was his first large-scale choral work. Quia respexit is an attractively relaxed soprano aria. Quia fecit mihi magna is a dramatic tenor aria, not unindebted to JSB’s setting. The fabulously expressive chorus Et misericordia points forward, like younger brother JC, to the Classical era. Fecit potentiam beefs up the bass (Bauer) with trumpets and drums, and vital rhythmic surges.

Suscepit Israel is lovely: almost Mozartian, slow and contemplative. Vermeulen excelled here again: hers is a voice I would happily travel to hear. All three composers exercise their skills at fugal writing, but CPE’s double effort here proves him a worthy successor to father and godfather (Telemann) alike. Carl Philipp is, in fact, one of the Baroque-Classical greats. It’s good that promoters and audiences alike are gradually waking up to that simple, long-hidden fact.