The audience went wild last weekend at the Spoleto Festival for a rather improbable theatrical experience: Stravinsky's unclassifiable and rarely performed opera-dance-mime spectacle "Renard." The applause seemed to be inspired not so much by the music (which still does not appeal to mainstream tastes, nearly 70 years after its composition) but by the most visible performers: four enormous, helium-filled balloons that were used as puppets.

In Charleston's tiny, charming and very old Dock Street Theatre, "Renard" shares a double bill for seven performances with a newer but more traditional opera in one act: Rafaello de Banfield's "Lord Byron's Love Letter," which has a libretto by Tennessee Williams. It was applauded, presumably, for expert stage direction (by the composer), some fine acting and tonal projection, and sets and costumes of the highest quality. In both works, the impact was seriously undermined by the fact that the words (sung in English) were often impossible to understand. So the audience had to settle for a cute gimmick in "Renard" and first-class staging in "Lord Byron."

When he composed "Renard" in 1917, Stravinsky suggested that the singers (two tenors and two basses) should be kept out of sight, with clowns, dancers, even acrobats -- but not balloons 20 feet high -- miming the characters of a Russian fable about a rooster, a fox, a cat and a goat.

The singers were visible in the Spoleto production, but that didn't matter much; they were dwarfed by the balloons, which clumsily but charmingly presented the story of how the fox caught the rooster (twice) but was driven away by the cat and goat. Beni Montresor, in charge of the staging, did his job effectively. But except for tenor Peter Gillis, the singers seldom managed to make their words intelligible. Some excuse might be found in Stravinsky's style for this work, which often uses the voices almost as though they were percussion instruments. But that style was not very vigorously observed.

In "Lord Byron's Love Letter," this production's style was perfect, and the music has a nostalgically romantic flavor that interacts well with the text. An old woman and her fortyish spinster daughter are living in reduced circumstances in New Orleans. Their only source of income is a love letter written by Byron that they show to tourists (from a distance; nobody is allowed to read it) in return for voluntary contributions. The letter was written to the old woman's mother after she met Byron briefly in 1824 while visiting the Acropolis.

Dark family secrets are revealed at the end, as one expects when the text is by Tennessee Williams. The fateful encounter of Byron with the young woman (who naturally loved him at first sight) is shown in a cleverly produced flashback sequence, played behind a scrim on an upper-level stage. The music neatly characterizes each of the characters (two tourists and the two women), and it generates some fine, rambunctious energy in allusions to a Mardi Gras celebration in progress outside the gloomy old house.

This opera, produced as well as it was at Spoleto, would work splendidly in the Terrace Theater, but in Charleston it suffered the same problem as "Renard": the words were frequently blurred, and considering the complexities of Williams' text, that is a serious problem.

One is tempted to blame the acoustics of the Dock Street Theatre, but some voices (Janice Myerson in a superb portrayal of the old woman and sometimes Lester Senter as a tourist) managed to project words effectively. The problem, really, is that many young American singers are taught to handle words effectively in every language but their own.