The 21-year-old opera "Vanessa," on public television tonight at 8 (Channel 26), is much like what might have occurred if Richard Strauss had collaborated with Gian Carlo Menotti.

This is hardly surprising, since the text is by Menotti. But from listening to it you would never know it came from the same man who has given us "Amahl and Night Visitors," "The Consul" and "The Saint of Bleeker Street."

The reason isn't just that the music was written by somebody else -- Samuel Barber at his most Straussian -- but that the play is such atypical menotti.

Normally Menotti's operas are relatives of Italian verismo , not so much derivative as simply logical progressions of Puccini, Leoncavallo, Mascagni and others. The texts are earthy, as is often the music.

Here there is hardly a trace of all taht, and the text might be by Chekhov, Ibsen or Bergman. In the score, Menotti himself emphasizes the contrast.

He places the work "at a country house in a northern country the year about 1905." And he is quite explicit about the theme: "The story of two women caught in a universal dilemma -- whether to blindly fight for one's ideals, or compromise and accept the truth that reality offers no solution but its own inherent struggle."

What comes between the women are, not surprisingly, two men. And the ambivalent resolution is, in its finest moments, worthy of the playwrights with whom the text has been compared.

The most crucial dimension is Samuel Barber's music. The orchestra carries a lyric impetus that is practically unmatched in American opera ("Porgy" comes to mind as the only one superior). In the last 20 minutes, beginning with one of opera's most eloquent quintet's, "Vanessa" is simply masterful. More than one critic has called it the finest American opera, and it is hard to disagree.

The television production came from Menotti's new spring Spoleto festival at Charleston, S.C. Sets, costumes and direction are very handsome. The cast is basically from the New York City Opera, Johanna Meier sings the title role, Henry Price the man who divides the house and Christopher Keene conducts.

Menotti may be the country's most noted creator of operas, but the finest work he has produced was composed by his long-time friend Barber. It is indeed worthy of Strauss -- say, "Arabella."