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It all started with a small box covered in intricate red and black beadwork. Bob “Hoff” Hoffman had taken up the harmonica in his mid-50s and wanted an attractive way to store and carry the instrument. He met an artist at the Smithsonian’s annual craft show in 2005 and commissioned a beautiful custom case, emblazoned with “HOFF” on the back, that he could wear around his neck. But when Hoff wore a blue and purple ensemble a few days later, the new accessory clashed with his get-up. He contacted the artist to request a second case in a new color combo.

A decade on, Hoff has amassed what he calls the world’s largest collection of handcrafted harmonica cases. (He’s still waiting on a response to his letter to Guinness World Records.) The Mount Pleasant resident, who moved to D.C. from New York 45 years ago, counts 500 unique cases in his collection, representing the work of about 450 different artists and crafters. Nearly half will be on view at Gallery O on H tomorrow through April 26.

In every country Hoff visits, at every art fair he attends, he finds someone who does commissions and works with him or her to design a functioning case with a personalized element—sometimes his name, sometimes an interpretation of his face. Each contains a working harmonica, which Hoff buys in bulk, but the thrill of the search for new cases soon overtook his actual practice of the instrument, though he occasionally plays in informal street gigs. “I’m a good harmonica player, but there are a lot of good harmonica players,” Hoff says, “and there are a lot of people who collect harmonicas.”

When it comes to harmonica-case collectors, as far as Hoff knows, he’s the only one. His online searches for artful cases have turned up few results, which is just fine by Hoff—the joy he takes from his collection stems from his collaboration with the artists he meets and learning the history of their craft. “When I think about when I’m most happy, it’s when I’m walking through craft fairs, talking to artists,” he says. “Trying to make a living with your craft—that’s a really noble thing to do.” One such artist, Carrie L. Rutherford, met Hoff at a faerie convention. The case she built him (above) features a polymer-clay likeness of Hoff with anatomically correct features hidden beneath the harmonica.

Most artists Hoff meets, of course, have never made a harmonica case before. Hoff gives them a short spiel about his collection and hands over a bulleted list of guidelines. (“Rule #1 – There is NO rush”; “Access to harmonica from case, so it can be removed and played”; “To be worn like necklace“) He must be pretty convincing: By Hoff’s estimation, 75 percent end up taking on the project. Now that he’s collected a critical mass, some artists have heard about his collection and offered to make him a case for free—including his 8-year-old grandson, who built one out of Legos.

Hoff collects his cases around themes. He likes things that move—there are four kaleidoscope cases in his collection (one pictured above), a slingshot, and one that functions as a mini pinball machine. A whole section of Hoff’s exhibition is dedicated to cases made in Vermont, where he spends his summers and puts his cases on display at a local farmers market. One of the Vermont cases (below), made of zippers, can be worn dangling casually or zipped up for “an evening at the Kennedy Center,” Hoff says. There’s also an international division with works from Jamaica, Mexico, Israel, Peru, Spain, Russia, and Kenya, among other countries.

And he’s got a special affinity for Abraham Lincoln, one of two presidents known to have played the harmonica (the other: Calvin Coolidge). Hoff leads walking tours of Lincoln’s assassination route, and one of his cases is a cylinder printed with the last photo ever taken of Lincoln and an image of the gun John Wilkes Booth used to shoot him. Another is an old Civil War gunpowder flask found in a Virginia battlefield; Hoff had it adorned with copper and split down the middle, turning it into a combination harmonica case and drinking flask.

From first discussion to delivery, this engraved ostrich egg case made by Virginia artist Tina Kannapel took three years to get to Hoff.

Now that he’s hit his original goal of 500 cases, Hoff is slowing down on the acquisition front to focus on organizing and showcasing his collection. In 2011, he won an Artisphere competition for local collectors of all stripes, which resulted in a two-month exhibition of his collection in the arts center’s Mezz Gallery, but the Gallery O on H show is his first in D.C. proper. When Hoff dies, he’d like to leave 50 or so cases with his ashes inside to family and friends, then donate the rest of his collection to a museum. Many have suggested Baltimore’s American Visionary Art Museum, which houses an impressive collection of work by self-taught artists, some of whom have made cases for Hoff. But he’s set on keeping his holdings in the District—in the Smithsonian’s craft-centered Renwick Gallery, for instance.

“I am a little bit of a pack rat,” Hoff says. But at 69 years old, the retired AARP employee and defense attorney has never collected anything else with such purpose and passion. To amass the world’s largest collection of anything was a surprise to him; even picking up the harmonica well into middle age was an unexpected life turn. Now, it’s become a prominent part of his identity. Most days, he picks out a case to wear that fits the occasion. (Lincoln came out on the 150th anniversary of his death.) He wears a baseball hat with a HOFF-labeled harmonica embroidered on it and signs his emails “Harmonically Yours.”

Hoff sees one big hole in his collection: D.C. artists. Fewer than 20 of Hoff’s cases were made in the District, and he’s made it a priority to commission work from more local artists and crafters.

The Gallery O on H show is a good start. Hoff hopes to attract the attention of D.C. artists willing to make a harmonica case, but his main goal, since none of the works are for sale, is to share the whimsy and keen craftsmanship of his collection with the world. It took Hoff two years to convince his wife to let him bring some cases down from the attic into their living room. Maybe local viewers will be a quicker sell.

An instrument inside an instrument—INCEPTION! This case is a working rainstick.

Photos by Amanda Hoffman