"I can't go on," sings Beverly Sills, "everything I have is gone." The vocal richness she brings to "Stormy Weather" contradicts what the words are saying; obviously she has a lot left and could go on for quite a while. But the sentiment is appropriate for her gala farewell performance at the New York City Opera, which happened last October but will be telecast at 8 tonight on Channel 26.

There is a neat symmetry in the way Sills rounded out her singing career at City Opera, where she has now become general director. It was 25 years, almost to the day, after she made he debut there; she began in the role of Rosalinde in "Die Fledermaus," and she took the same role for her final appearance -- but this time there was a difference. Only the second act, the party at Prince Orlovsky's, was performed. There was no time for any more, because the party was interrupted and prolonged by nearly as score of guest appearances -- performers such as Leontyne Price, Placido Domingo, Renata Scotto, James Galway, Donald Gramm, Sherrill Milnes, Eileen Farrell, Bobby Short and Mary Martin who came to pay a final tribute to their colleague, with Carol Burnett acting as mistress of ceremonies.

Perhaps the high point of these walk-on performances is Scotto's rendition of "Over the Rainbow," with a charm and vocal quality that might convert even hard-core Judy Garland fans. Gramm gives a stirring rendition of "I Want What I Want When I Want It." with added lyrics that compare Sills to her managerial colleagues in Boston and Chicago: "Now Sarah Caldwell and Carol Fox/Are girls with prodigious wills./But nothing in Boston nor Chicago/Can ever rival NYCO/And the fiery redhead that makes it all go;/I'm speaking of Beverly Sills."

The Sills performance of "Stormy Weather" comes in the middle of a long musical debate with Burnett over the merits of operatic versus torch singing. Before it's over, Sills is singing blues and Burnett tries a few bars of Puccini.

This is a unique event. It is not always equal to its best moments -- the most that one can say about Kitty Carlisle's singing of Orlovsky is "chacun a son gout" -- but there are some moments of pure magic and many of pure fun.

After the Sills spectacular, Channel 26 will run a less lavish but musically interesting half-hour presentation: Zoltan Kodaly's "Hary Janos" suite with narration and some dramatic monologues by Vincent Price. The Kodaly music, with its lilting melodies and bright orchestration is a classical top-40 item, but the opera from which it is taken is virtually unknown. Price dressed in a Hungarian officer's uniform that makes him look like a hotel doorman, explains the enormous musical sneeze with which the music begins, the musical clock that gives the orchestra's brass and percussion sections some healthy exercise and the music for the battle scene in which Hary Janos, a humble Hungarian peasant, single-handedly defeats Napoleon and his whole army.