When Bryan Cheng was 3 years old, he watched his older sister Silvie play the piano onstage and realized he wanted to play an instrument, too.

After being told he was too young for the drums, too small for the double bass, and he found the violin "too squeaky," Cheng "fell in love with the dark and deep sound" of the cello.

"I think playing music together bonds us more than the usual sibling relationship would," the 22-year-old pianist said about performing as the Cheng² Duo. "It's nice with our age gap and that [Bryan] brightly chose at the age of three not to play the same instrument helps."

The Cheng² Duo played for the second time at New York's Carnegie Hall last Sunday night in the Weill Recital Hall with a program of their favorite classical pieces, including works by Mozart, Chopin and Brahms, and two world-premiere compositions written for the duo by Canadian compatriot Alexina Louie.

"People say that classical music is dying out, like we usually see grayhaired people in the audience," the 15-year-old cellist said. "We really want to get the younger generation more involved in classical music because it's great - there are so many new things to be discovered."

The Cheng siblings said they like to push the boundaries of classical music and working with the Juno Award-winning - the equivalent of the US Grammy Award in Canada - composer has helped them to this end. "We really enjoy working with a living composer because sometimes you'll play something by Beethoven or Mozart and you'll be thinking, 'Is this right?' and you can't ask them because they're not here anymore," Silvie Cheng said and laughed.

"That's what we like about the living composer because you get to put in your own ideas and you can actually communicate," Bryan Cheng said.

The duo performed an earlier work of Louie's, Bringing The Tiger Down From The Mountain II, at their 2011 Weill Hall recital debut. After their positive experience, the duo requested Louie to compose a new cello and piano piece, which resulted in Pond Mirrors Bright Sky and Wild Horse Running.

"We always want to bring contemporary pieces to new audiences and broaden everyone's ears," said Silvie Cheng, who was raised in Ottawa.

Louie said she sought to reflect the supportive relationship between the Cheng siblings in her work Pond Mirrors Bright Sky, which is a dynamic piece that ends with a playful finale that suggests sunlight playing on the surface of a pond.

The young musicians' Chinese zodiac signs inspired Wild Horse Running. Louie originally thought Bryan Cheng was born in the Year of the Horse, but found out later that it was instead Silvie Cheng who was born under this sign. The Chinese-Canadian composer sought to convey the power and speed of the horse, as well as the poetry of its motion.

One special feature of the new works has Silvie Cheng reaching into the inside of the piano and plucking at its strings, which emits a thunderous, almost ominous sound. Meanwhile, her brother spends some time thumping on the neck of his 259-year-old cello and yanking at its strings like an angry bassist.

"What do you think?" a beaming Silvie Cheng asked the audience after the duo premiered the works and the applause had died down. "Not bad for a Canadian, eh?"

At this, a group of friends and family in the front of the hall cheered with pride.

As a result of working with Louie, the siblings formed the Cheng² Duo New Music Fund in March to continue commissioning orks by other living composers for concert halls.

"This young duo is bristling with great talent and enthusiasm," Louie said. "they exude energy and commitment in their playing and do everything to bring the new composition to life."

The new works are dedicated to the memory of Bryan Cheng's cello teacher and mentor since 2006, Yuli Turovsky, who passed away in January from Parkinson's disease.

"[Turovsky] was always known for his generosity both offstage and onstage," he said about the late conductor and cellist who founded the I Musici de Montreal chamber orchestra in 1983.

"It was like [he and his orchestra] were giving everything with every concert just in case, because you never know when the last concert really is," Silvie Cheng said. "We try to adopt the same approach."

The Cheng siblings also credit their parents for exploring the world of classical music with them and allowing their interests in music to flourish.

carolineberg@chinadailyusa.com