After many years of being one of the most distinguished string quartets in the business, the Hagen Quartet finally made its Boston debut on Sunday, courtesy of Celebrity Series of Boston. True, stateside visits seem to be rare for this quartet, which was born in Salzburg, Austria, in 1981. Nevertheless, this was an unjustly belated debut.
The program - Beethoven, Haydn, and Mozart - might appear shockingly conservative, and a lesser group would have made it sound so. But the Hagen is not most groups. The quartet - the three Hagen siblings, Lukas (first violin), Veronika (viola), and Clemens (cello), with second violinist Rainer Schmidt - finds a way to play subtly yet unmistakably with a piece’s basic elements. Phrasing, color, tempo, and voicing are varied in a way that makes familiar works sound fresh, even radically new. What sets the Hagen apart is that the performers achieve this with an effortless, polished sound, and without the music ever coming off as mannered. Their interventions may not sound natural, but almost always they feel inarguably right.
Beethoven’s “Serioso’’ Quartet (Op. 95) sounded even more fiercely compressed than usual. Phrases one was used to placing in the background - particularly the inner voices - suddenly took center stage. Notes were held just a fraction of a second longer for emphasis, without disrupting the musical flow. It takes astonishing control and ensemble work to bring this off, though it would have been even more effective without some uncharacteristically out-of-tune moments from Lukas Hagen.
Haydn’s “Joke’’ Quartet (Op. 33, No. 2) showed how a musical phrase can begin in one character and end in a different one, still seeming spontaneous and artful. The first movement’s development has rarely sounded so deeply conflicted, undercutting the image of Haydn’s music as pleasant and civilized. But the Hagen also brought out the piece’s humor - not just the false endings in the finale, but also the woozy slides in the trio.
Mozart quartets are more likely to open a concert than close it, but the Hagen put the Quartet in D Major (K. 575) at the end - fitting for the masterpiece that it is. In one sense, this was the most straightforward performance of the afternoon, but its extreme refinement and intelligence also put it on an exalted level. The slow movement induced one of those rare moments of transport in which everything external seemed to fall away; there was nothing to separate you from the interiority of the music, which you couldn’t imagine unfolding in any other way.
There was one encore: the opening movement of Beethoven’s first quartet (Op. 18, No. 1), which had a tempestuousness reminiscent of the “Serioso’’ that had opened the concert. The Hagen is a treasure; the quartet should return as soon as possible.