Who was the greatest teenage composer? Mozart? Schubert? Michael Jackson? My choice would have to be Felix Mendelssohn, and not because he was so prolific with string symphonies. Rather, he created, before the age of 20, a pair of works – the overture to “A Midsummer Night’s Dream” and the Octet for Strings – that are unrivaled for melodic invention and sheer exuberance.

On Wednesday evening at Alice Tully Hall, two fine 30-something quartets – the Pacifica and the Miro – joined forces to present the latter, under the auspices of the Chamber Music Society of Lincoln Center.

Now in its 11th year, the Pacifica (Simin Ganatra and Sibbi Bernhardsson, violins; Masumi Per Rostad, viola; Brandon Vamos,cello) is in residence at the University of Chicago. The quartet began the program with Beethoven, specifically the Quartet in G major, Op. 18, No. 2.

From the outset, I knew this would be a fine performance. The initial phrasing, like Ms. Ganatra’s tone, was deliciously delicate with just a hint of coquetry. The group made much of the narrative aspects of the work, rendering the Adagio cantabile as a pageturner of an affecting story.

The sound of the ensemble was superb. The blending made me think of one hydra-headed instrument. These people have been together long enough now that they even breathe at the same time. Perhaps the overall sonic impression was a bit more gleaming than polished, but this was still a very good effort.

Next came the “Intimate Letters” Quartet of Leos Janacek. The Pacifica players acquitted themselves credibly for this white-hot piece of December passion squandered on a May recipient (Janacek was in his 70s, and dreamed about an amanuensis in her 30s).There was much to admire about this reading, including a subtly constructed shifting of tempos employed to good effect in the Moderato. Particularly haunting were the enunciations of remembered dances, specters of an inner nostalgia used as emblems of an outward seduction. Ultimately, this ghostly playing seemed to be saying that Janacek was actually not so much enamored of Ms. Stoesslova as of his own youth.

My only objection to this realization was the heavy emphasis on the composer’s unusual string effects. In a brief talk beforehand, Mr. Per Rostad reveled in these flutter-tonguing and tremolo devices. The Pacifica certainly mastered them, but offered a little too much cinemascope for my taste.

After intermission the Miro Quartet (Daniel Ching and Sandy Yamamoto, violins; John Largess, viola; Joshua Gindele, cello) made its sole appearance, occupying the inner chairs of the Mendelssohn. These very good musicians are in their 10th season together, and I expected a ripping good collaboration for the Mendelssohn.

But it was not to be. A morass of bottom-heavy plodding took me by surprise during this woefully deficient reading. If ever a piece cried out for delicacy, this is it. The Mendelssohn Octet should be airy, diaphanous, heavenly.This night it was stuffy, ponderous, and decidedly earthbound. Perhaps a switch wherein the Miro group had sat in the first chairs might have helped. It certainly would have provided variety. Oh well, two out of three ain’t bad.

Abraham Mendelssohn the banker once described his life by saying, “For the first half I was my father’s son; now I’m my son’s father,” referring to his position in the lineage from the philosopher Moses Mendelssohn to the famous composer. In retrospect, though, Felix’s gifts were fleeting. The rest of his life, although highly significant as a contribution to music history, was not blessed with the level of inspiration he displayed in his teens.All the more reason to present these jewels in as glittering a state as possible.