When the esteemed Emerson String Quartet returns to Ann Arbor Sunday afternoon to kick off the University Musical Society’s Chamber Arts Series, the fare is the ultimate: the last three Mozart string quartets, plus the Mozart Adagio and Fugue in C Minor, K. 546. There are reasons aplenty why the last should be first on this concert by an ensemble many consider first in its field. The Emersons made these “King of Prussia” quartets—so called for their association with musical monarch Frederick William II—the first project for their new recording label, Sony. The CD is due out in November.

Surprisingly, the Emersons—Eugene Drucker and Philip Setzer, violin; Lawrence Dutton, viola; and David Finckel, cello—have never recorded these quartets before.

By 1991, when the world commemorated the 200th anniversary of Mozart’s death with abundant concerts and festivals, the Emerson had completed recording the six Mozart “Haydn” quartets—Nos. 14-19 of Mozart’s 23 total—a project the group began in 1988 for Deutsche Grammophon. The six “Haydn” quartets, especially the famous “Hunt” and “Dissonance” quartets, have continued to be a cornerstone of their concert repertoire. But as far as recording goes, violinist Drucker said in a recent phone conversation, “We basically have not recorded any important Mozart in 20 years.”

“There was no intention behind that,” Drucker added. And the three King of Prussia quartets coming up Sunday have been in their repertoire since just about the time they learned the “Dissonance,” so they are old friends. The question arises whether these three last quartets—Mozart envisioned a set of six, but completed only the three, under monetary and personal duress—are a summation of sorts, in the manner of the late Beethoven or Schubert quartets.

“That’s not the case here with Mozart,” Drucker said. “It’s hard to point to an arc of progress from the Haydn quartets of the early 1780s to these quartets of 1789-90. It’s hard to say that these are more advanced than the others.”

Two things are different, though, as he sees it.

One is the prominence of the cello part. “That has something to do with Frederick,” he said, “who was a great amateur cellist and had one of the greatest cellists of Europe, Jean-Pierre Duport, in his employ. I assume Mozart did it to please him.”

The other thing that distinguishes these last quartets is their minuets, Drucker said. “Two of them—K. 589 and K. 590—have striking minuets that are far more developed than in the earlier quartets.”

Still, he said, “you can’t talk about ‘late style’ in the quartets the way you can talk about it in the last three Mozart symphonies, a few of the viola quintets or the last Da Ponte operas.” On the other hand, listening to these last quartets is an immersion in music “so beautiful and crystalline,” Drucker said. “It’s a master at the height of his powers.”