The beginning of K590’s second movement lacks any marks of articulation, but in the fifth bar Mozart adds staccato dashes. Many groups, the Alban Berg Quartet, for one, don’t change their playing at this point, but it’s typical of the Hagen Quartet that it makes the difference as marked as possible, with the opening sounding particularly smooth, and the staccato bars extremely short. The effect is certainly striking, but is it perhaps a little contrived?

Listening to this CD, such questions recur quite frequently – they’re the downside, maybe, of performances (and a recording) of the most beautiful clarity. Tone, balance, phrasing and intonation all play a part in conveying this impression, as does the highly effective use of vibrato, mostly reserved for individual expressive lines. At their best, in the first movement of K589, for instance, the Hagens give us an amazingly vivid, luminous vision of the music. And some of the boldest strokes are particularly successful; in K589’s finale the unmarked ritardando just before the modulation to D flat (track 8, 1'56") brings to the fore a sad, meditative feeling that lies behind the high spirits. My overall assessment would be that this is remarkable, enthralling playing, but that the Hagen Quartet, playing Mozart, doesn’t always have the knack, (possessed to a notable degree by the Quatuor Mosaïques), of imparting an air of spontaneity, however many freedoms are introduced.

It’s good to have three substantial quartets on a single CD, but several of the longer repeats have to be omitted.