At 101 years old, Gertrude Matthews is still the life of the party.
"She loves parties, she likes to drink, she likes to dance," said one of her many fans, Diane Tosi.
"She lives by herself. She dresses herself," said another, Melinda Hassen.
Matthews' secret is the piano. Twice a week, for two solid hours, she dazzles her friends and fans with musical performances at a Palm Beach restaurant. She's so beloved that one fan sent her a big gift -- a donated piano to play at home.
Watch Gertrude Matthews' story tonight on 'World News With Diane Sawyer'
Matthews has been playing the piano since the Great Depression, and she believes music is what keeps her young.
"I like the tunes. I pick out music that I like. It's tuneful. It's rhythmic," she said. "I thrive on it."
Her doctors said the piano does more than invigorate her spirit. They believe her music and her connection to her listeners has kept her mind and heart in perfect health over many decades.
Matthews has outlived her husband and two of her children, but today, her only ailment is arthritis, which she said is no big deal.
"I wake up in the morning, I thank God that I'm awake and able to put my feet down on the ground," she said.
Her story is of great interest to Dr. Thomas Perls, a researcher at the Boston Medical Center who has studied thousands of people who have lived past age 100. Perls said that Matthews and many of the others he's studied are better at managing stress, more outgoing and more optimistic, even about aging.
"They don't dwell on things. They don't internalize things that are stressful," said Perls. "We have people like Gertrude whom we call escapers -- those who have entirely escaped age-related diseases even at 100, and she shows tremendous promise in my mind of going on to 105, 110 or older."
Perls and other scientists believe that most people have the power to extend their lives by simply changing their frame of mind.
Gertrude Matthews has a few helpful tips of her own:
"You've got to behave yourself, No. 1," she said. "And no smoking."
Matthews said that drinking is OK as long as it's in moderation, and, for that matter, everything is better in moderation.
"Except if you play music, do a lot of it!" Matthews said.
She's living proof, she said, of why you should always do what you love.