As students in Swansea, Matt Furtado and Erin Horne warbled their way across the stage as high-school sweethearts Danny and Sandy in Grease. In the process, they turned into real-life sweethearts themselves, whose show-biz dreams blossomed along with the romance.

Now, six years and two college degrees later, they wow crowds across the globe in the Sesame Street Live show Elmo's Coloring Book. He plays the human character Professor Art and she cavorts as both Ernie and Oscar the Grouch.

They'll appear at Lowell Memorial Auditorium next Thursday through Sunday in the perennial January favorite. And, they say by phone from Lima, Ohio, they feel great returning to Lowell, where they auditioned for VEE Productions, the show's producer.

"I grew up inspired by (Muppet creator) Jim Henson, so it's a dream come true for me to work with them," said Furtado.

"We feel incredibly fortunate to have auditioned together and to be in the same show," said Horne.

The couple, both in their early 20s, have fond memories of watching Sesame Street as they grew up.

"Ernie and Oscar were two of my favorites when I was growing up, so it is fun to be playing them. Ernie is a ball of energy and I get to use my puppeteer skills with Oscar," Horne noted.

Furtado attended Sesame Street Live shows in Providence, R.I.

"I'd see the show, then go home to act it out in the basement with puppets," he said.

Both attended Rhode Island College in Providence for its musical theater program. They first auditioned for VEE in 2004, then landed in its other live show, Dragon Tales, after graduating in 2005. They found their way into Sesame Street Live last August and have toured ever since.

"I was going to play Bert, but I ended up as Professor Art and performed it first in Mexico City, lip-synching the part in Spanish," Furtado said.

They also toured the Caribbean and Puerto Rico, bringing Sesame Street Live there for the first time last fall.

"The response was tremendous. In the Bahamas, they had never had a family show like this with life-size characters. You should have heard the kids. They thought they were going to see a TV show, so the place went crazy when the show started," said Furtado.

"We felt like we were rock stars in Mexico City. It was incredible," said Horne.

Elmo's Coloring Book explores emotions through colors and poses the question of what might happen if colors disappeared. As Professor Art, Furtado takes Elmo and his friends on a trip into their drawings of ancient Egypt, the land of dinosaurs and a very musical junkyard.

"We blow up Elmo's coloring book to life size and have a great time," he said.

Horne has fun playing two characters -- even if she wears size 15 shoes as Ernie.

"I just know I have to make extra big moves," she said.

Family and friends will come see the show here, including Horne's brother, Brendan, a freshman at UMass Lowell.

"He's planning on bringing his posse to the show," she said.

Performances run Jan. 25-28. Tickets are $14-$27. Opening night, all seats $12, except premium Gold Circle. Available at the box office at 978-454-2299 or through Ticketmaster at 617-931-2000 or www.ticketmaster.com.

Nancye Tuttle