But back then, she was a man named David.
When Buechner came out publicly as a transgender woman in 1998, the musician risked it all, lost it all and has been working over the past decade in Canada to get it back again.
"Canada was my salvation in many ways," said Buechner, 54, before a recent concert in Montreal. She is to play in Edmonton on Monday, part of a packed schedule that matches the 60 concerts a year she performed during the height of her career as a man.
But there is no more New York Philharmonic. No American Symphony in Carnegie Hall.
"It seemed like the skies were certainly open to a lot of big orchestras and that all just closed down. It was just gone," recalled Buechner.
After coming out, she was shut out of the conservative concert scene in the U.S. and, despite earning some money teaching children piano lessons, was on the verge of becoming homeless.
So she moved north.
"The conductors and presenters in Canada were much more open, because they hadn't really known me," Buechner said. "They judged me on the music itself."
As a child growing up in suburban Baltimore, Buechner knew she was a girl as much as she knew she loved playing Mozart.
Her grandmother once made her a purple coat with a frilly white shirt so she could dress up as the historic composer. But when she wore the outfit to school, other kids beat her up and a teacher sent a note to her parents asking that David not wear girl's clothing to school again.
It was then, Buechner said, that she stuffed away her desire to be a girl. Her acceptable passion for the piano became her life.
The prodigy studied on full scholarships at Juilliard in New York and made the city her home for nearly 25 years while her career flourished. As David, she played at the White House. She won international competitions.
But it wasn't enough. One day, while resting on a rock in Central Park, Buechner made up her mind to start living as a woman.
"I couldn't — I wouldn't — hide that anymore ... I was just going to be myself."
She had been warned that ditching a tux for a gown on stage might end her career, so she wasn't surprised when some concert presenters and orchestras wouldn't return phone calls.
"I was a little more stunned that people who had been longtime friends deserted me, particularly conductors."
She was also "harassed out" of a teaching job at an elite music conservatory; dozens of other schools refused to hire her.
Over the next few years, Buechner said, she struggled. A man tried to rape her, assuming she was a "trannie sex worker." She travelled to Thailand for sex-reassignment surgery, but the doctor turned out to be a "butcher" and she later needed corrective surgery.
There were bouts of drinking and "half-hearted" suicide attempts.
But when Buechner's mother called her child's old piano teacher to tell him David was now Sara, the senior only asked whether it was spelled with an 'h.' It was inspiring, said Buechner.
"It tells you that despite lives and times and generations, there are people who have a superb view of humanity."
In 2003, Buechner accepted an offer to teach at the University of British Columbia and headed for Vancouver, where she still lives with her wife.
Buechner says none of her students have questioned her past as a man, and it's breathtaking to see changing social attitudes. She once swapped stories with a student, a transgender trumpet player, who transitioned at 14 with the blessing of his parents.
Buechner has performed across Canada and Asia and, slowly, she's getting more invites to play in the U.S. She has been featured twice by the San Francisco Symphony, but she's still frustrated she's not entirely welcome back in her home country.
Besides pounding the piano on stage, she has a job telling her story. In 2012, she spoke before a standing committee on human rights in Ottawa. Last year, she wrote an essay about her life that ran in the New York Times. She received hundreds of letters from transgender people and responded to them all.
It's important for her to stand up and show people they don't have to be afraid to be who they are, she said.
"I wonder and kind of hope that stories like that become more and more rare as the years go by, so that it's not a huge deal when someone is transgender, when someone is gay, when someone is green," Buechner concluded with a laugh.
"Human beings just come in all those varieties."