In Caroline Shaw's Entr'acte, the string quartet is asked to sound nothing like a string quartet. They create an airy effect several notches below a whisper. Two players tick-tock while the other two chime. We pass through a section in which Philip Glass meets Harold in Italy, and then move on to some instrumental moans and sighs.

It was the Calidore String Quartet bringing these sounds Sunday afternoon to a Philadelphia Chamber Music Society concert. The performance marked the local debut of both the work and this gorgeous young ensemble.

Shaw's Entr'acte comes from 2011, and it speaks pointedly of our time. No sooner has one idea come into focus than Shaw gets distracted by the next. It is like some musical newsfeed. Just keep scrolling, the piece seems to urge. The something next must be something better.

The Calidore was the perfect ensemble for this work, though it turned out they were perfect for everything on this program. PCMS introduced the quartet Sunday in the relatively small Benjamin Franklin Hall of the American Philosophical Society, but it seems likely they'll need a bigger venue next time.

The group, which formed in 2010 at Los Angeles' Colburn School and which is now based in New York City, won a coveted 2018 Avery Fisher Career Grant and has landed professional management. What might a return engagement someday bring? Their encore, the "Romanze" movement from Brahms' String Quartet. Opus 51, No. 1, raised all kinds of happy prospecting thoughts for the rest of the piece.

Composer Caroline Shaw
Kait Moreno
Composer Caroline Shaw

Quartet and composer hitch their wagons to each other this summer when the Calidore gives the premiere of two new Shaw works for string quartet at the BBC Proms in London. The foursome has an amiable mix of technical precision, expressivity, and an ability to turn on a dime that beautifully animates Shaw's prismatic tendencies.

Of course, you could say those are qualities held dear in any work for string quartet.

Individually, these players weren't flawless, but, more important, they weren't machines. First violinist Jeffrey Myers took chances, but judiciously, and they almost always paid off in detailed, expressive phrasing. A similar temperament came from cellist Estelle Choi. Violist Jeremy Berry was slightly something else — warm and refined, but with a color that sometimes focuses intensely. Second violinist Ryan Meehan had a way of rising from the texture in surprising flashes of bold color.

Sunday afternoon at the American Philosophical Society, the Calidore String Quartet.
Pete Checchia
Sunday afternoon at the American Philosophical Society, the Calidore String Quartet.

The repertoire highlighted these qualities. The roles in Prokofiev's String Quartet in F Major, Opus 92, are those of co-equals, and the Calidore handed off ideas to each other seamlessly. Another Shaw work, First Essay: Nimrod, was an easy hybrid of repeated patterns and unexpected moves, like a surprise slide up to another key. (The two works planned for the Proms are her Second Essay: Echo and Third Essay: Ruby.)

If there was much to admire in the Calidore's handling of Shaw and Prokofiev, the Ravel String Quartet in F Major was something to love. The third movement was the highlight. Beautifully introspective, this music can sometimes lose direction. Not here. So smoothly did the Calidore handle transitional moments that all of its eerie reveries, pangs, and mysteries flowed into a single current toward final ethereal resignation.