At a misty Broad and Spruce late Wednesday night, the street musician riffed on a fleet, rather loose-limbed clarinet adaptation of Barber's

Adagio for Strings

. In America, everyone from busker to filmmaker can lay claim to the piece. But a few minutes earlier, in the Perelman Theater, the Dover Quartet was declaring its musical lineage to Barber in a more formal way.

Founded at Curtis in 2008 as the Old City String Quartet, the Dover renamed itself after the composer's atmospheric setting of Matthew Arnold's "Dover Beach" for voice and string quartet, written in the 1930s while Barber was still a student at Curtis.

The young quartet - Joel Link, violin, Bryan Lee, violin, Milena Pajaro-van de Stadt, viola, Camden Shaw, cello - programmed not only that work, but also the full string quartet from which the Adagio comes. Along with a Beethoven quartet and an appealing new piece by Curtis professor Eric Sessler, the crucibles seemed to multiply: Could the Dover be both of Curtis and the first great full-time string quartet to come out of the city since the old Curtis String Quartet faded away more than three decades ago?

Controlled and polished, the Dover is nothing if not perfectly unified. Could there be a finer, more homogenous pop than the one the players produced in the pizzicato section at the end of Beethoven's Opus 135 String Quartet in F Major? Nothing could have remained on a composer's wish list by the end of Sessler's 2013 String Quartet, whose first movement was full of reverberations and refractions on optimism and sincerity, and the same kind of American vibe that infused Barber.

What was often missing, in the Beethoven especially, were strong opinions. Technically, the Dover is all there, having mastered the slippery mechanics of listening, blending, echoing, and all the other subtle moves that often stand between a young ensemble and total cohesion.

Beethoven is an invitation to more, however - the human element. Funny that the quartet was a replacement on this Philadelphia Chamber Music Society concert for injured violinist Pamela Frank, who has those qualities in spades. Beethoven's second movement set off in a brilliant, clockwork dash. But so serious. The sublime third movement was gentle, but not profound. Must it be more to be Beethoven? It must be!

And my guess is that the Dover will get there someday. Beethoven in all his fullness - the suddenly dark corners, the vulnerability, the elation - is a lifelong pursuit. Putting space around the music to explore meaning would have brought greater impact to the grisaille-in-sound of "Dover Beach," too. Rose Bampton and Barber himself were two early interpreters. Here, Curtis student Jarrett Ott brought charisma, a rich sound, and sensitive diction to the work.

Meticulous detailing suited Barber's String Quartet, Opus 11; the clarity of the performance revealed the construction of the outer two movements, marvels of economy both. It's liberating to hear the middle movement unmoored from funereal associations. Not too slow, not prone to wallowing - perfectly adhering to the "molto adagio" marking - the Dover wasted no energy on being sentimental. How could they? Here, youth was not wasted on the young.