Reprinted from yesterday's late editions The Potomac, the Rhine and the Nile were in and round the music Sunday night at Kennedy Center, but to the three sopranos in concert, all from Memphis, the river of of rivers is the one of their childhood, the Mississippi.

A soft summer downpour greeted the crowd arriving for Memphis Night, with 100 Memphians on hand to holler for their girls, the first of whom was Ruth Welting in the same kind of innocent cotton dress a girl might wear to a dancer at home.

"Such a voice from such a little person," said Madeleine Sanford, a retired government worker who had come in from Montgomery County to see if Memphis singers have grits in their glissandos (they don't). And sure enough, she sang one of the sweetest songs there is, Bellini's "Come per me sereno,? a favorite of Tetrazzini, Galli-Curci, Callas and Sutherland - who were all once as young as she.

Next came Nancy Tatum, sheathed marvelously in clothlike, plum-colored steel scales, with the passionate aria from "The Consul."

"Ah, now we have opera," said a Lillien Barnes, another retired government worker who holds that a big voice should leave you limp and purified at the last.

Mignon Dunn, best-known of the three singers (her Met debut was in 1958) strode forth in a changeable metallic dress banded like the layers of the sea, beneath her red hair an elegant face which by some stroke of luck has grown more beautiful in structure with the years. She sang Delilah's love song for Samson.

Alis Goldate, a Memphis housewife-singer-mother-poet, who arranged Memphis Night because she was damned proud of her town had four singers at the Metropolitan Opera (Gail Robinson did not appear because she is having a baby), arrived with a group of 31 who had flown up with her: bank presidents, foundation chairmen, opera buffs.

She worked more than two years with the endless details of such an evening, and did not even check the box office, though the concert benefited a singer scholarship in Memphis.

All these people grew up in a city more famous for steamboats, jazz, river disasters, floods, lumber, murder and politics than for interpretations of, or even performances of, Bellini.

But somewhere along the line it occurred to each of the singers that a throat can do more than growl, and that no matter what the world has been, they themselves could transform a measure of experience and a measure of the usual distress and despair of humans into something magical, and therefore real.

You could not tell who in the audience was from the banks of the Mississippi, and you had no idea, even if they were pointed out to you, what their memories were.

When Amneris and Aide sang together, for a minute there was a rage and suffering that sounded familiar, but which is, of course, common to all towns. When Brunhilde sang the culminating aria of The Ring,there was some of the exultation, some of the awareness of failure, the bowing to fate, the arrogance of assertion and the reaching for glory that is known as well in one place as another.

The audience was not large, a third of the seats empty; but it went wilder than usual. Nothing was said of the bluffs facing west, nothing of the sun as strong as this world knows, nothing of the river.

The singers might as easily have come from Norfolk or Denver as from the town on the river. For many in the audience it made a difference where they came from. The singers sang free for the occasion. Something, not that you could very well say what, sang loudly back.