by Andrew Lloyd Webber and Tim Rice opens at City Hall tomorrow evening for a 10-night run.

Karen Musson takes on the role of Eva Duarte, who was born poor and illegitimate and rose to become the second wife of Argentine president Juan Peron. Having reduced her country to virtual economic ruin, she died of cancer in 1952 at the age of 33.

Karen Musson heads a cast that includes Joel Froomkin as Che, who as the narrator of the show, symbolises the opposition of the two dictators. As Mr.

Froomkin puts it, "Che is the voice of reason, crying out in the dark.'' Brian Webb takes on the role of Peron, with Stephanie Butler as the Mistress and Keith Madeiros as Magaldi, the night club singer.

The show marks the directorial debut of Janice Moran, while Tom Ray is musical director.

`Evita' is a special challenge for Mr. Ray says producer Marjorie Stanton, because it is more of a modern opera than a musical and is almost entirely sung through.

"This is a very different show than anything we have done before,'' concedes Mrs. Stanton, "I am sure that people will enjoy it because the cast and orchestra is excellent. We have some very fine performers and I think everyone will be thrilled to see what Coral Waddell has done with the choreography.

There is a great deal of dancing in `Evita' but she is using people who are not necessarily trained, but showing them to their best advantage.'' She feels a very high standard has been attained by the principals' singing and is full of praise for the rest of the cast: "They have to play such a variety of roles -- from aristocrats, to peasants and the military!'' Mrs. Stanton pays tribute, too, to Bruce Hallett, who is bringing years of expertise to ensuring that a highly complicated show runs smoothly. "Evita alone has 11 changes of clothes, so the pace is amazing.'' There are still some tickets left but some evenings are already sold out.

For this reason, all tickets ordered by telephone (excepts patrons' tickets) must be picked up at the Visitors Service Bureau or from the City Hall box office must be collected by 12 noon today, or they will offered for re-sale.

`Evita' runs from tomorrow, October 5 through October 15 at 8 p.m., with a matinee on Sunday, October 9 at 3 p.m. (Seniors admission at $12). There will be no performance on Thursday, October 13.

ANOTHER SUITCASE IN ANOTHER HALL -- Stephanie Butler, far left as Peron's mistress, contemplates her fate after she is evicted by the ambitious Eva Duarte.

HIGH FLYING ADORED -- Che, left , played by Joel Froomkin sings, in reflective mood of Eva Peron's stranglehold over his country, as Eva prepares for her Rainbow Tour of Europe.

ON THIS NIGHT OF A THOUSAND STARS -- One of the most popular numbers in `Evita' is sung by the tango singer Magaldi (Keith Madeiros), who takes the young Eva Duarte to Buenos Aires and launches her on the path to fame and infamy, below left . Also seen are dancers Louise Cabral (left), Dee Edmunds and chorus member Joe McGann. Mr. McGann appeared in the Warwick Academy Players (forerunner of G&S) production of The Mikado over 20 years ago.