Music plays through Kristy Hamilton’s life.

It was the sound track of her childhood. It powered her youth. It sustained her through tough times. And it is inseparable from her success.

A psychology professor at the University of Maine at Machias, Hamilton plays trombone in university-town band and – on the piano – accompanies other musicians of all stripes at area concerts. And she sings in the Community Choir.

On top of all that, Hamilton is the piano tuner of choice for many players, teachers, churches and schools throughout Washington County.

“I guess you could say I grew up surrounded by music. My father, James Hamilton, is a musician and also tunes pianos and pipe organs,” she said. “I used to sit under the piano keyboard while he worked. I’d ask questions and he’d explain things as he worked. I was unconscious of it at the time, but I was learning the trade. The most important thing he taught me, I guess, was how to hear, how to really listen to the instrument.

“The other day I remembered that my daughter, when she was younger, she sat underneath the pianos while I tuned,” Hamilton said. “Who knows? … Maybe there’s a future tuner in the making.”

Growing up in Youngstown, Ohio, Hamilton joined the school band during the sixth grade, initially tackling the baritone. By the time she reached high school, she had switched to trombone – primarily because that is what the band needed. By her senior year, three out of seven classes were music, an officially frowned-upon emphasis on one subject.

Hamilton continued her musical studies at the Dana School of Music, Youngstown State University. She got married as she entered her third year, however, and subsequently, “put away” a lot of her music and instruments to raise a son and daughter.

“I did have a piano and I played that, but I did miss playing the trombone,” she said. “Most of all, I missed playing with other musicians.”

About this time, Hamilton began tuning pianos for much needed income. Tuning pianos gave her opportunities to get out of the house and at least keep in touch with the musical community.

Hamilton reluctantly put music to the side for eight years. Then she became a church organist.

A year later and divorced – “Not related to playing organ at the church,” Hamilton said – she decided to return to school and complete a degree in music. But she was unable to attend the day classes that the program demanded because as a single mother, she was working a number of jobs – crafts store clerk, sign maker, waitress for one “horrible” month, picture framer, church choir director and college laboratory assistant.

Consequently, she concentrated on her minor – psychology – and, going part-time while working full-time, she earned her bachelor’s degree in three years.

A faculty member brought up the idea of graduate school. Hamilton acted on the suggestion and, last year, was awarded a doctorate in psychology from Indiana University in Bloomington. Drawing on a special interest in neuroscience, her doctoral work was an in-depth study of the song processing of cowbirds: specifically, the role of a particular brain nucleus of female cowbirds in discriminating individual male cowbird songs.

Music had provided a gateway into a categorically distant and seemingly unrelated field of study.

“When I first went to grad school, I studied … bats. It was my music background and my interest in the auditory system that led me both into that and into studying song processing in birds,” Hamilton said.

She accepted a position at UMM in 1999. Hamilton, 40, has an unaffected affability that makes her a favorite teacher among students.

As she settled in, she began exploring the Down East music scene. Her first discovery was an old friend – Gene Nichols, professor, musician, performer and leader of the town band and community chorale.

When Machias figured in Hamilton’s future, the town’s name sounded vaguely familiar. It turned out that Nichols had mentioned Machias years ago as his then-new teaching post. That connection eased Hamilton’s entry into the band and larger Down East musical community.

And word of her piano-tuning skills spread quickly. Soon she was visiting homes, churches and schools with her case of tuning tools, like a doctor making house calls, toting a black satchel of instruments.

As with many experts – the articulate ones, anyway – and artists, when Hamilton explains the how of tuning a piano, it all seems fairly straightforward. Basically, the task involves a tuning fork, miles of muting tape and a tuning hammer. The hammer was handed down to Hamilton by her father, as were a few other tools in a starting kit.

A piano usually takes one to two hours to tune, depending on the instrument.

An “ornery” piano can take longer. Hamilton defines an ornery piano as one that jumps in pitch, instead of changing gradually, when a person tries to tune it. “You keep bypassing the right pitch,” she said.

Pianos that get “normal” use need to be tuned about every six months, according to Hamilton. The more the piano is used, the quicker it will go out of tune. It is important not to let the instrument go too long without a tuning, even if it is not being used. The best time to have your piano tuned is after a season changes, say, in early winter or early summer.

“The worst thing to do to a piano is keep it in a place where the humidity is constantly changing,” said Hamilton. “Moisture swells the wood around the tuning pins and, when it dries out again, the pins don’t hold in place as well. Moisture is a piano’s worst enemy.”

Part of the enjoyment of tuning derives from Hamilton’s penchant for fixing things, she said. She likes to roll up her sleeves and tinker. Years ago, Hamilton bought her first piano, an abused baby grand minus pedals, completely unplayable, for $75. She broke out the tools and brought it back to life.

“Bringing an instrument to its most beautiful prime condition is very satisfying,” Hamilton said. “There is something very satisfying about creating, especially in the realm of sound. And tuning allows me to help other people to create beautiful music.”