When the acclaimed pianist Jon Nakamatsu, winner of the 1997 Van Cliburn International Piano Competition, has performed here in recent years, it’s often been in multi-piano ensembles, like last year’s three-piano rendition of “Rhapsody in Blue” at the Aloha Piano Festival.

This weekend, he’s getting into another multiple piano work, but with a full orchestra as well.

With local pianist Lisa Nakamichi, the organizer of the Aloha Piano Festival and a touring artist herself, he’ll be playing Mozart’s “Concerto for Two Pianos” with the Hawai’i Symphony Orchestra. It’s something he’s looking forward to, for the enjoyment and the challenge.

“There’s so much good stuff written for two pianos,” said Nakamatsu, who has close family ties to Hawaii, in a phone call from his California home. “But I would say that, out of all chamber music, it is probably the most difficult of all collaborations, primarily because if you don’t play together, you hear it immediately. … You hear the hammers strike, and if you can’t coordinate that, it just sounds like … raindrops on a roof.

“But this concerto by Mozart, it’s just such beautiful, joyful, fun music, who wouldn’t want to make the attempt?”

HE AND Nakamichi will be tested the moment they start playing. The concerto, which is believed to have been written by Mozart to be performed with his sister Nannerl, begins with a short introduction from the orchestra, then has the two pianists launching into a trill together.

“It’s right in time, and has a little little ‘nachschlage’ (grace note turn) at the end, so you have to do that together, and if you don’t, by the next measure, you’ll know that it hasn’t been done together. It’s almost comical that if you don’t start together, and don’t end that note together, then any pianist in the room will smile and go, ‘Oh, that’s funny.’ I think that’s part of the joke.”

Nakamatsu’s parents were born here and he grew up coming to Hawaii frequently from his home in California and “just going going around the islands with my cousins,” he said. “A real local experience, I suppose.”

One thing he didn’t do was learn how to surf. But when he talks about his life as a performer, it almost sounds as daring as a competitive surfer taking on a big swell in a contest.

“Performers pretty much exist on the standard that if your playing isn’t improved by the presence of an audience, then you’re probably not a performer,” he said. “If somehow that experience, that public experience, as terrifying as it always is, doesn’t inspire you go to beyond what you’re doing in your practice room, then performance probably isn’t for you.

“When that happens, it’s certainly an exhilarating thing. That’s the thing that keeps us motivated as performers, even though we’re terrified most of the time.”

NAKAMICHI FIRST performed with Nakamatsu back in the early 2000s at a celebration for Ellen Masaki, the longtime doyenne of Hawaii piano teachers and Nakamichi’s teacher. She spends much of her time in Japan, where her husband works, performing in Tokyo in January as part of her efforts to expand the reach of the Aloha Piano Festival. After that, she traveled to California to work with Nakamatu, spending three days to “take the concerto apart and decide on shaping and interpretation.”

Though Nakamichi played one movement of a Bach triple piano concerto with the old Honolulu Symphony Orchestra, this is her first time playing a complete double concerto with orchestra. There’s a lot to figure out, so during their practice, they played not only their parts, but the orchestra’s part as well.

“The challenging part for me, was that, normally, when you’re playing as a soloist … you just need to be aware of the orchestral ‘tutti’ (orchestra playing alone) and then your entrance. But here, you’re dealing with two other people,” she said. “You have to know John’s part, you have to know where the orchestra comes in, and then you have to know how to put the cadenza together so that it sounds together. … You want to make it as consistent as possible.”

Leading the orchestra will be maestro Hans Graf, an Austrian-born, Russian-trained conductor who conducted and produced a recording of Alban Berg’s “Wozzeck,” which won the 2017 Grammy for Best Opera Recording.

In addition to the Mozart, Graf will lead the orchestra in Bruckner’s popular “Symphony No. 4, ‘Romantic.’” Though written during the era known as Romantic period of music, Bruckner’s nickname actually refers to a rather dreamy, nostalgic imagery he was trying to convey: horns announcing the opening of the gates of a medieval city, knights in shining armor “on proud horses” riding out into the forest, birds chirping and a mid-day carnival.