Sunday was Mirella Freni Day at the Metropolitan Opera. Fifty years ago, the Italian soprano made her operatic debut, and 40 years ago, she made her Met debut. The company celebrated these facts with a gala on Sunday afternoon, a fairly emotional show featuring six singers, plus Miss Freni herself.

A little well-known history: Miss Freni was born in Modena, the same town as Luciano Pavarotti. The most famous trivial fact in opera is that the two of them shared a wet nurse. “You can see who got all of the milk,” she is quoted as saying. She quickly became an international star, a singer known for technique, purity, and refinement. She was a wonderful Mimi (in “La Boheme”), and excelled in many other roles as well. In recent years, she has sung a good bit of Russian repertory, Tchaikovsky in particular.

Sunday’s gala began with the overture to “The Bartered Bride” (Smetana), with James Levine in the pit. (Needless to say, the Met Orchestra was on hand, as was the Met Chorus – as was a children’s chorus.) Mr. Levine made a singularly great recording of the “Bartered Bride” overture – with the Vienna Philharmonic – and his reading on Sunday afternoon was not so great, or correct. Did they rehearse this baby? Run through it? At any rate, it was passable.

Then it was time for Mirella Freni to appear. She emerged in the company of Joseph Volpe, the Met’s general manager, and seemed overcome. I thought for a second that there would be an announcement: She couldn’t sing. But that was a dumb thought.

As the audience stood and roared for her, Miss Freni put her head on Mr. Volpe’s shoulder. In due course, she dismissed him, crossed herself, and began to sing “Adieu, notre petite table,” from “Manon” (Massenet). She had some serious intonation problems, as she would most of the afternoon, and French has never been her best language – but we were there simply to hear Mirella again, and she effected a touching diminuendo at the end of the aria.

She would not sing again for another full hour.

The first of the “guests” was Frederica von Stade, the beloved American mezzo, who sang “Connais-tu le pays?” from “Mignon,” by Thomas. This aria was far too slow, and a bit mannered, and it was strange that Mr. Levine did nothing about it (about the tempo, at least). But Miss von Stade showed off that gorgeous, wet, superbly draped sound, and the crowd adored her. (Am I allowed to say that “Flicka” is still a looker, after all these years?)

Then came Salvatore Licitra, the Italian tenor whom the music business is simply determined to make a star. In “Un di, all’azzurro spazio,” from “Andrea Chenier” (Giordano), he was big-voiced and bold, as usual – also flat and blustery. But this music rather lends itself to Mr. Licitra’s style of singing.

We then heard the Prologue from Boito’s “Mefistofele,” not with Samuel Ramey – the American bass associated with this opera – but with another American bass, James Morris. It was a pleasure to hear his snarling, savvy self. And Mr. Levine and his forces – including that children’s chorus – performed their hearts out, which the music needed.

Next it was the turn of another Italian tenor, Marcello Giordani, who gave us “Cielo e mar,” from “La Gioconda” (Ponchielli). He employed the histrionic method, and some of his pitches were approximate, but he was undeniably operatic, in one sense.

And then, finally, Miss Freni returned, for an aria much favored by veteran sopranos: “Io son l’umile ancella,” from Cilea’s “Adriana Lecouvreur” (“I am but the humble servant of the creative spirit”). Miss Freni did some lovely, exemplary soft singing. And then Mr. Licitra joined her for a duet from “Adriana,” in which the tenor did some gross sliding around, and in which he cut the soprano no slack at all: He did not lessen his volume, which disadvantaged her. (I should note that the orchestra played with exceptional beauty, in this duet.)

The second half of the gala was all-Russian, and, in fact, all-Tchaikovsky, beginning with the big aria from “The Maid of Orleans.” Miss Freni sang it winningly: It was subtle, small-scaled, and exquisitely shaped. For the first time of the afternoon, we heard music making of a high order.

And then we had the entire third act of “Eugene Onegin,” purveyed by Miss Freni, Dmitri Hvorostovsky (the Russian baritone), and Robert Lloyd (the British bass). (I should not forget Mr. Levine, who is merely an unsurpassed conductor of this opera.) Mr. Hvorostovsky is ever reliable, and Mr. Lloyd displayed that magnificent instrument – he was a little rough, but still Lloydian. The main thing was to honor, and hear, Mirella Freni.

It’s not every day, or every season – or every decade – that the Met honors a top singer. Why it chose Miss Freni is a bit of a puzzle. Plenty of excellent singers hit the age of 70, and receive no gala. What was it that the comedian Red Buttons used to say, at those Dean Martin roasts? “He never got a dinner.” People like to say of Miss Freni that “she is the last in a line,” of Italian sopranos. This is not necessarily to be taken seriously. In the piano world, how many “Last Romantics” have we had? A hundred? This is a marketing device, and a nostalgist’s sigh, more than anything; it does not correspond with reality.

Nevertheless, it will be a shame to be without Mirella Freni. At least there is an ample recorded legacy. No, the gala was not officially labeled a farewell. But it surely felt like one. Then again, so did her appearance on the Met’s opening night, 2002. You never know, in opera more than in most realms.