"Das Rheingold," Wagner's epic prologue in that equally epic operatic tetralogy "The Ring of the Nibelung," received a truly memorable performance last night at the Kennedy Center Concert Hall. John Mauceri conducted the National Symphony Orchestra and a cast of solid singers.

This "Rheingold" was a concert version, overwhelming at some of the climactic moments, like the majestically paced and stunningly played "Entry of the Gods Into Valhalla" that concludes the one-act work. Even those much-publicized 18 anvils--tailor-made in F-natural spread over three octaves--made a grand sound, a quite beautiful one, in fact.

But most important, this "Rheingold," which will be repeated tonight, was a milestone for music in this city, in several important senses.

First, there was Mauceri. Despite his relative youth, he has conducted probably more fine opera performances in Washington than any other single individual--from "Mass" to "The Rake's Progress" to "La Bohe me." But this was his first Wagner, which in its symphonic complexity--especially in "Das Rheingold"--is a sort of ultimate test.

Last night's performance was as assured technically, interpretively and otherwise as anything Mauceri has done. Those astonishing 136 bars portraying the motions of the river Rhine are so grand that they evoke the whole scale of the 15-hour "Ring," not just the 2 1/2 hours of "Rheingold." This passage is a cruel test of a conductor's steadiness, but that was never even remotely in question last night.

Performing Wagner this well permanently changes one's sense of a conductor's potential, and perhaps his own. Mauceri's wonderfully stylish Rossini has proved that he has wit and style. But his Wagner proved that he has power and control--and those are the qualities that have come to matter most with the modern symphony orchestra.

It was a "Rheingold" of clear textures and unlagging momentum, not as Germanic as the traditional kind. If it did not have quite the kinetic force of Solti's famous performances, that was not always to the bad. Stylistically, there were similarities to the Boulez Bayreuth version, which has brought the "Ring" very much back into fashion as a result of this year's televised performances. But there was more passion, and a concern with richer textures, than the Boulez--which is to say it was a better performance.

This "Rheingold" was also a milestone for the National Symphony, which had yet to have a chance to lavish its new-found excellence on full-length Wagner. There was discipline galore last night. It seems almost unfair to single out specific sections, but the trumpets, which carry so many of Wagner's most important and heroic, played with such ease and tone that they must be mentioned. The horns, after a shaky start, also played well.

Wagner has always been Washington's weakest point operatically; in fact the National Symphony believes that this version is the first "Rheingold" here since Sol Hurok brought a version in 1929.

So perhaps the most important thing that this "Rheingold" demonstrated was that local institutions need no longer go outside to produce first-rate Wagner. There has been local Wagner before, but the performances of the past that linger in the mind were from companies on tour, like last year's overwhelming "Parsifal" under James Levine during the Met's visit.

What the National Symphony has proved with this bold move is that such dependency should be over. We now have a conductor and an orchestra to do our own Wagner of real quality.

It would be a terrible shame if the opportunity were not grabbed to do our own "Ring" cycle, following the story of the death of the gods to its end, with a "Walku re" next, then "Siegfried" and then "Go tterda mmerung." They could become regular summer events.

This production proved that casting might not be as hard as it would seem. The singing, on the whole, was not brilliant, but it was never bad. In that most crucial of roles, the King of the Gods, Roger Roloff, was sonorous but stiff at the beginning. During the final moments, however, he was singing with real power.

He suffered by comparison with the performance of the wily, conniving Loge, god of fire, by the redoubtable George Shirley. He had a vocal beauty and dramatic control that would have graced the stage of any company.

Fricka, Wotan's wife, was phrased well by Margaret Yauger, but there was vocal strain. That other principal figure, the evil dwarf Alberich, was well sung by Julian Patrick, but perhaps because he was reading from a score, there was little of the creature's frenzied desperation.

Among others, voices that sounded outstanding were Patricia Stone as Freia and Malcolm Smith as the giant Fasolt.

Alessandra Marc got off to a particularly lovely start as one of the Rhinemaidens, and Geraldine Decker was her usual forceful self as the earth goddess Erda.