Jack Hopkins, 94, demonstrates his talent for the harmonica, an instrument he has played for nine decades. (Julie Zauzmer/The Washington Post)

Jack Hopkins keeps a harmonica in his pocket everywhere he goes.

He buys the instruments in bulk so he can hand them out to new acquaintances, and he plays 16 varieties himself. He plays high and low harmonicas, plastic and metal ones; he plays a minuscule harmonica that is less than 11 / 2 inches long, and a massive one that is nearly two feet long.

Sometimes, he plays two harmonicas at once.

And he has been playing for nearly 90 years.

Hopkins, 94, found his first harmonica in his Christmas stocking when he was 5 or 6 years old. Once he realized that he could play a complete scale on the simple plastic toy, he started teaching himself songs. Within weeks, he surprised his father by tooting recognizable tunes — his first, he thinks, may have been the 1917 song “The Bells of St. Mary’s.”

(Julie Zauzmer/Post)

The popular songs of his youth are still his favorite ones to play, he said. Demonstrating the varying tones and ranges of the harmonicas in his collection for a reporter — he has more than 40 — he played snatches of “Misty” and George and Ira Gershwin’s “I Got Rhythm.”

After whistling out “Danny Boy” on a chord harmonica, which has two slides, Hopkins said enthusiastically, “The only place you can get these is on the used market, because they stopped making them.”

As a child growing up in upstate New York, Hopkins was a lackluster student of piano and flute, but his enthusiasm for the harmonica stuck. It appealed to him above other instruments, he said, because he could carry it with him.

He whiled away summers perched with his harmonica in the branches of a buckeye tree in his back yard. He stopped playing only while he served as a radio operator in Europe during World War II — the best harmonica manufacturer was a German company, he recalls, and he worried that if he broke his instrument during wartime, he wouldn’t be able to get it repaired.

When he moved to Northern Virginia in the 1960s for an engineering job, he decided that after decades of self-taught playing, he might benefit from a few lessons. In search of a harmonica teacher, he called music stores, to no avail. He even tried the local musicians union and learned that only one member played the harmonica, as a secondary instrument, and did not want to teach.

So Hopkins, who now lives in Lake Ridge, decided to become the region’s harmonica instructor.

He taught classes for many years at community centers in Arlington and Fairfax counties and at Northern Virginia Community College. He traveled to harmonica conventions all over the country and befriended people whom he describes as the world’s biggest names in harmonica performance.

He even enjoyed a week-long engagement at the Kennedy Center in the mid-1980s. The San Francisco Ballet came to town to perform accompanied by the National Symphony Orchestra. The score called for a harmonica, and Hopkins got the call. “It was wild but not impossible. I could keep up,” he said. “I borrowed a tuxedo from my neighbor.”

About 25 years ago, after he found two other amateur aficionados of the chromatic harmonica — a more sophisticated instrument than the toy store variety, because it includes a slide that can create sharp and flat notes — Hopkins founded the Capital Harmonica Club. During its weekly meetings at Wesley United Methodist Church in Alexandria, at least 15 people played together.

These days, regular attendance has dwindled to two. But Hopkins shows up every week and extends an open invitation to anyone interested in learning to play.

“I’ve outlived them all, or they’re all in nursing homes,” Hopkins said. “I’d love to get some young people to teach.”