These are, in their own modest way, quite daring interpretations of Beethoven’s six ‘early’ quartets. There have been other recordings of Op 18 on period instruments, of course, including a recent set by the Eybler Quartet (Coro Connections, 5/18 and 9/19), who – also quite daringly – present the works at the breakneck metronome marks Beethoven appended later in his life. The Narratio take an entirely different tack, however, by applying flexible tempos (based on evidence suggesting ‘that such modifications were an important and integral part of the revered “German style”’ as championed by Louis Spohr and Joseph Joachim) and abundant use of portamento, as described in Spohr’s 1833 violin method.

The Narratio present the six quartets in the order in which they were composed, so we begin with No 3, and right away leader Johannes Leertouwer swoops up from the first note to the second. Now, I’m a huge fan of portamento, but this threw me for a loop at first, perhaps because it sounds ever so slightly inelegant (a faster and lighter slide might be preferable), and later left me perplexed as the application of portamento feels a bit haphazard. For example, at the start of the recapitulation, this same ascending motif is played (down an octave) by the second violin and repeated immediately after (at the original pitch) by the first, yet only the first violin slides. There are many lovely (and elegantly expressive) uses of portamento scattered throughout this set – as in the opening of No 1, some 13 bars in, where it underscores the first violin’s sighs – but greater consistency would be more effective and ultimately less distracting, too.

As for tempos, the Narratio’s choices tend towards the leisurely, and when combined with the ‘flexible’ stretching of phrases and rests, the result can be sluggishness, as it is in the outer movements of No 5. Also, the tempo-shifts sometimes create a sense that the music is episodic. Flexibility can be marvellous, yes, but not if it continually impedes momentum. The booklet tells us that the ensemble’s name ‘refers to the art of rhetoric’ and ‘the quartet’s focus on storytelling’. And they can be riveting raconteurs – the finale of No 6 (with its melancholy introduction) is a case in point. But all too often I found that the many tempo adjustments meant that narrative thrust is sacrificed for incidental detail. I felt this in the opening movement of the C minor Quartet: the colours they produce are richly saturated but stretching sforzando accents, as they do at 1'41" and elsewhere, is more intrusive than illuminating.

The Narratio are most satisfying in the first and second quartets, and No 2 is especially lovely for its lightness of touch and rhythmic point. Taken as a whole, the Narratio’s set serves as a fascinating foil to the Eybler’s. Somewhere between the Eybler’s mad scramble and the Narratio’s micro-managerial approach, there’s an ideal that reveals why these works remain so astonishing.