The success of the Da Ponte trilogy overshadows Mozart’s penultimate opera, “La Clemenza di Tito” (“The Clemency of Titus”), which was given a spirited performance on Sunday at the Rose Theater as part of the Mostly Mozart Festival. Written in 1791 and having its premiere just three weeks before the Magic Flute — and just nine weeks before the composer’s death — the work was not staged in America until 1952 at Tanglewood. For many it remains, like Shakespeare’s “Titus Andronicus,” a piece that they have heard of, but never actually experienced.

It is rather a slapdash affair, relying heavily on recitative not composed by Mozart but rather his pupil Franz Xaver Suessmayr, the man who finished the Requiem. But there is much good music to be extracted, and it was played impressively at this performance by the Orchestra of the Age of Enlightenment.

The group is a period instrument ensemble, woodwinds actually made of wood, long bore trumpets, natural horns with multiple, interchangeable crooks. In the past, this band has been guilty of some desiccated realizations, guided by the period fanatics. With conductor Edward Gardner at the helm, however, the music was a charming combination of emotion and Classical restraint.

Mr. Gardner is the new music director of the English National Opera, and is blessedly not a period specialist; in fact, he leans toward the modern. He established right from the overture a willingness to incorporate drama, pity, and power into the mix. The singers also adopted this aesthetic, with mixed results.

This was a concert version of the opera, with the Concert Chorale of New York in the back of the orchestra and the soloists out in front with music stands. There was a certain informality to the proceedings as well, evidenced by the remarkable heterogeneity of wardrobe.

Fiona Murphy was a solid Annio, a female in a male role. She blended nicely with the sweet voice of Sarah Tynan as Servilia, particularly in the duet “Ah, perdona al primo affetto.” Hillevi Martinpelto was somewhat shaky as Vitellia, tending to sharp her higher and louder notes and missing several key spots during runs. In her defense, arias like “Deh se piacer” are as difficult as — and stylistically quite similar to — the two killer solo numbers for the Queen of the Night in the contemporaneous Zauberfloete.

Matthew Rose was strong as Publio, resonating deeply and prodigiously. Toby Spence seems to envision the innate gentleness of Tito as rather foppish, making the central decision of whom to take as his bride forcing a major suspension of disbelief. Technically, his “Del piu sublime soglio” was fine, but this listener had a hard time associating it with his character.

“Tito” is also notable for its instrumental history. The festival this season is featuring Mozart’s Clarinet Concerto in a later concert, and there is a direct connection to this opera. Infatuated with the new instrument, Mozart composed two magnificent set pieces with clarinet obbligato and even convinced his friend Anton Stadler to travel to Prague to perform them at the premiere. The most famous also has become the big number of the opera, often excerpted for recitals and singing competitions in the mezzo range.

Alice Coote, who did such a splendid job as Hansel at the Metropolitan this past season, was back in another hosenrolle, the loyal but conflicted Sesto. Her “Parto, parto” was magnificent, filled with genuine emotion and superb pitch control. Antony Pay accompanied on the basset clarinet — a wooden instrument with additional bottom notes — and, being on the stage, was able to enjoy and acknowledge much of the enthusiastic ovation engendered by Ms. Coote. You can’t do that from the orchestra pit.