Beyond image, her success is founded on a stunning ability to mimic the sounds and rhythms of the Vietnamese language. Like few other foreigners, she can catch its subtleties of tone and diction, softening consonants, flattening vowels, sliding her voice over its intonations -- without understanding a word.

"It's a gift from God, that's all I know," she said in a recent interview after a recording session here.

But perfecting it has taken hard work. Dalena selects her songs for their melodies and only learns the meaning of the lyrics after she has memorized their sounds. "I listen to the songs in earphones over and over again," she said. "Sometimes I fall asleep at night with the earphones on. Basically, you have to try to turn your tongue upside down, so I'm studying all the time."

O NCE she has learned the songs, Vietnamese friends explain their meanings, she said, and she re-translates their explanations into English lyrics, often inserting them as added verses.

In a conversation at a local coffee shop -- Dalena is not a lover of Vietnamese food -- she said she began to imitate foreign languages as a child in Florida, where the family moved from Indiana. Lingering over tea with her mother, Darlene Arenberg, who is also her manager, Dalena said she did not realize that her ability was something special until people began asking, "How can you do that?"

Until a few years ago she worked as a ticket seller at Disney World, where visitors from around the world thought she was a native speaker when she offered a greeting. Dalena, a devotee of martial arts, often rented Chinese movies, and found herself picking up Cantonese. Then, she said, about five years ago she memorized a song in Cantonese and, at the suggestion of an acquaintance, also memorized one in Vietnamese.