Keys to the city

"I am not there to show my muscles on stage," says Hamelin, 47, the Canadian-born pianist who makes his debut at the Rockport Chamber Music Festival tomorrow. "Music ain't the Olympics. What can I say? I'm up there doing everything I can to make a singing instrument out of what is theoretically a percussion instrument. I want it to shout, sing, whisper, and do everything in between. I believe there is no more complete instrument in conveying human emotion."

As he views it, the praise for virtuosity, used by supportive critics and even in his own promotional materials, gives a false sense of the musician as a bloodless speed merchant. Yet his cult reputation has been boosted by his decision to record unfamiliar classical pieces that are, at times, supremely challenging. Many of Hamelin's 58 CDs champion such worthy yet underappreciated composers as Alexander Scriabin, Karol Szymanowski, and Charles-Valentin Alkan.

But tomorrow's performance will show another side of the pianist. Live, Hamelin's range and love for more familiar works come through. Yes, he'll take on Alkan, but he'll also play Mozart, Liszt, Haydn, and Faure. The key, the musician says, is to offer audience members an education without losing them.

"I don't really consciously give them what they want, but I do try to be considerate in not overloading them in things they do not know," says Hamelin. "If I'm going to include something unusual, it won't be the whole program."

Hamelin, speaking at his home on Commonwealth Avenue, recently moved here after three decades in Philadelphia to live with his fiance, WGBH radio host Cathy Fuller. (They will be married as soon as his divorce from singer Jody Karin Applebaum is finalized, he says.) In April, Hamelin will make his Symphony Hall debut with the Boston Symphony Orchestra. This year he performed for the first time with the Saint Louis and Seattle symphonies. After years as an appreciated cult figure, Hamelin's career has taken a decided upswing.

With each concert, Hamelin surprises even longtime fans of his CDs. Count former Chicago Symphony Orchestra Association president Henry Fogel as one of them. He attended the Seattle concert and followed by raving about the pianist's performance on his blog.

"I had heard recordings but not heard him in person," says Fogel, now a senior advisor to the League of American Orchestras. "I was just knocked over. He plays with a wonderful sense of freedom, but never once do you think he distorts the music. The virtuosity is extraordinary but what I don't think I was fully ready for was the soft playing. It just drew you in."

Hanako Yamaguchi, the direc tor of programming at Lincoln Center, had a similar experience. She was moved by Hamelin's tone and phrasing after watching him perform Mozart at a private event.

"It was very simple and when he played it, there was a feeling of great space around each of the notes. The melody really floated," she remembers. "He's one of these pianists, I think, who can do anything."

There are several theories as to why it has taken Hamelin so long to break through to major symphonic gigs. He admits his previous management - which he declines to name - was passive. He's had much more luck since signing on with Colbert Artists Management, the respected agency that also represents Alfred Brendel.

Then there's Hamelin's stage manner. Some speculate that his un-flashy style - his hands move fast but he sits relatively still at the keyboard - might hurt him in a business ruled by physically expressive soloists such as Lang Lang.

"He's not a showman. He's a player," says Minnesota Orchestra music director Osmo Vänskä. "His movements are very small. Minimal. Other guys might have big huge arm moves and they try to jump with their whole body, those kinds of visual signs. But as a conductor, if I have to make a decision between a showman who is not a great player and a real musician like Marc-André, my decision is for a real musician."

In Rockport, along with the Mozart and Haydn, Hamelin will tackle Alkan's "Symphony for Solo Piano Op. 39, Nos. 4, 5, 6, and 7." The piece, Hamelin notes, requires great stamina in certain passages. The texture is also complex.

"It makes high demands in almost every respect, whether mental, emotional, or physical," says Hamelin. "It could also be said that it does take courage to present anything unfamiliar on stage and to convince audiences of its worth. The difficulty is double with such demanding pieces as this one. It's a little easier for me since I've literally had it in my ears for 40 years."

For a musician known for taking on such difficult pieces, Hamelin is relatively low-key about his schedule. He does not keep track of how many hours he sits at the piano, though he says he practices 24 hours a day. By that, he includes sleep hours, during which he believes he might turn over a composition in his head.

Strangely, in Newton, Hamelin doesn't have his own piano, though he's planning to buy one. Instead, he uses Fuller's, which sits in the basement next to the stacks of his sheet music collection. Downstairs, he also has a genuine death mask of one of his heroes, the late Russian composer Nikolai Karlovich Medtner.

He's thrilled to be in Boston. Born in Montreal, he moved to Philadelphia originally as a teenager to study at Temple University. So far, he's taken in concerts at Jordan Hall and heard the BSO at Symphony Hall under music director James Levine.

"I would describe this as Philadelphia times three or four," says Hamelin. "I'm constantly struck by the diversity of ensembles, the diversity of repertoire."

Hamelin looks forward to the big concerts, particularly the BSO appearance.

"It's to keep the ball rolling and water the lawn constantly," he says. "Unfortunately, it doesn't take too long for the general public to forget about you. But the bottom line is, I don't do this for myself. I do this to entertain. And share with them the miracle of human creativity."

Geoff Edgers can be reached at gedgers@globe.com