Patients and staff members smile when they see him in the hallway.
"We've always been friends," says Ruth Hopkins, 75, a patient with multiple sclerosis and osteoporosis.
Brandenburg's helping hands are vital to Hopkins, who no longer has use of hers. He visits her several times each week, feeding her dinner and writing and addressing greeting cards. He also accompanies her to high school and family reunions and other events.
Hopkins says she loves to hear Brandenburg sing. At the request of one of her roommates, Brandenburg performs "Vagabond Shoes" and "Old Shantytown."
Moving down the hall, he stops to talk to Larry Mey, 42, who was in a motorcycle accident when he was 17.
"He's a pussycat; he likes people so much," Brandenburg says as Mey kisses a visitor's hand.
Brandenburg also has forged a special bond with Tony Crowder, 37, an automobile accident victim who's been on a respirator for 13 years. Crowder, a quadriplegic, cannot speak and is fed through a tube.
"He's very dependent on me; he's very private," Brandenburg says.
Crowder communicates by moving his eyes as Brandenburg recites the alphabet, indicating which letter he should stop on.
"I'll gradually spell out words and sentences," Brandenburg says.
They watch "Jeopardy!" together, and their interest inspired them to create four books called "Trivia by Tony and Hugh." Once a month, Brandenburg leads trivia sessions for patients.
Each year he plants flowers on a second-floor deck in memory of Richard Cogan, a patient who had Lou Gehrig's disease and died in 1990.
Brandenburg's photos hang throughout the center, and at Christmas he gave each patient one of them. He also takes pictures to document holiday parties and other events at the center.
Brandenburg taught Spanish at University of Texas in Austin, Texas, from 1949 until 1960. The Hagerstown High School graduate started taking photos in 1942 after saving enough money from his first job at R.M. Hays and Brothers to buy his own camera.
Fourteen of his photographs are on display in the Baer Gallery of Washington County Museum of Fine Arts in Hagerstown through Sunday, Aug. 17. The exhibit includes landscape, portrait and abstract works, as well as two of his bird photographs.
Brandenburg, a member of Trinity Lutheran Church in Hagerstown, took pictures for the church during its renovation last year.
He is dedicated to his hobby. One sweltering morning last week he spent four hours under a camouflage sheet, trying to capture a pair of bluebirds on film.
His photography, so inspiring to those at the center, is what led him there.
Brandenburg talks to local groups about his bird photography, and the center's volunteer coordinator was in the audience at one of his lectures. She asked him to speak at the center, and he agreed.
He started volunteering in April 1981. It isn't always easy.
"I go home very tired at night, sometimes quite frustrated by things that happen," he says.
Brandenburg has some health problems himself - he has had a form of chronic fatigue for years, and the sight in his right eye is failing.
He says he's just one of many who help the patients at the center, and he'll continue as long as he's able.
"It's nice to know you're needed," he says.