Lisa Walsh can't read music, and she has trouble picking out notes on the piano. But there's no doubt about it: the 24-year-old sure can sing.

Behind this unlikely combination is a rare genetic condition called Williams syndrome. It's characterized by developmental delays and other particularities, yet for reasons that have mystified researchers, it also leaves many of those afflicted by the syndrome with special musical ability.

Tomorrow, Walsh will share her talent with Montrealers, joining the children of jazz great Duke Ellington on stage for a fundraiser at Concordia University's Oscar Peterson Hall.

"She's just a natural and a joy," said April Ellington, who, with her brother Edward - the other half of the Savoy Ellingtons - first practised with Walsh in January. "I just found her to be brilliant and a quick study," she said.

Asked why she loves singing so much, Walsh clearly had difficulty putting the whys into words.

With a compact disc playing the musical accompaniment, she gave a small sampling of her ability in her parents' living room. She sang each note with warmth and depth, and exuded a playfulness that would endear her to any audience.

The fundraiser is for the Concordia Centre for the Arts in Human Development, where master's degree students planning a career in art or music therapy run a program for adults with developmental disabilities. Walsh attended the program for three years after finishing high school.

Lenore Vosberg, the program's acting director, explained that about 40 students with disabilities attend the program during the school year.

As part of the program, they also put on a full-scale musical. In 2000, Walsh was given the star role in the play And Alice Dreams.

"We didn't know how well she could sing until we saw her in that role," Vosberg said.

Walsh's parents, Nancy and Bruce, though nonmusicians, weren't as surprised, having been told by teachers at a music camp Lisa attended for several summers that their daughter was indeed gifted.

For several years, Walsh sang with the Cantabile Chorale, a West Island group, and performed with the West Island Chorus of Sweet Adelines.

For the past two academic years, Walsh attended Berkshire Hills Music Academy, a special school in Massachusetts where she also learns skills for daily living. There, she's part of a jazz ensemble and sings in choirs. "I really love singing," she said.

What makes her a great singer is that she's so secure in her pitch, Berkshire Hills faculty member Dirk Litzner said in a telephone interview.

"Probably her most outstanding talent is that she can memorize or repeat any song or music she hears, almost immediately," he said.

"Lisa probably knows hundreds and hundreds of songs.

"Lisa will put on a great show for any great audience. Her stage persona is just going to glow."

I Can! A Celebration of the Arts and Ability takes place tomorrow at 7:30 p.m. at the Oscar Peterson Concert Hall, on the Loyola campus of Concordia University. Tickets are $30 and are available at the box office or through the Admissions network by calling (514) 790-1245. For more details, go to http://oscar.concordia.ca

For more information about Williams syndrome, visit the Web site at www.williams-syndrome.org

dparkes@thegazette.canwest.com