Duluth, Minn. — At the Wal-Mart in Superior, Wisc., just across the harbor from Duluth, the aisles are full of people pushing carts loaded with Barbie dolls and Gameboys.
At the back of the store, Bob Greenberg and his three sons are warming up. They've squeezed their chairs into an opening between the baby clothes and a rack of brassieres.
Half-a-dozen shoppers stop in the aisle and listen to the Greenbergs' rendition of "Joy to the World." One woman applauds. Another drops a dollar into the metal donation pail.
The Greenbergs started playing for the Salvation Army last year to raise money for the food shelf in Superior. The food shelf was running low, and the Greenbergs decided to help out. They didn't play music at first -- they just gathered donations.
Then one day, they hauled their instruments down to a grocery store, and they played at the Salvation Army kettle in the parking lot.
"When we didn't play, people stopped dropping money," Bob Greenberg says. "And as soon as we started playing, the interest and the excitement picked up, and all of a sudden money was dropping rapidly into the kettle."
So he decided they should try again. He and the boys brought their instruments to a shopping mall. When they finished playing, the kettle had $500 in it.
Bob Greenberg plays the tuba in the family quartet. He learned when he was a kid, but he set it aside for 20 years. His son Josh got him hooked on the tuba again. When Josh was six years old, he asked for a saxophone.
Josh says his dad bought him one.
"We still have video tapes of him trying to make me play," Josh says. "I used to hide under the piano bench because I used to hate practicing."
Josh laughs, and points at his brothers.
"Then he started up, and he started up, and my father finally picked it up, too," he says.
Now, no one has to drag the Greenberg boys out from under the piano bench to play. They play in their high school band. They play at a local college. David, the trumpeter, plays with the Duluth-Superior Youth Symphony.
They grumble about the charity gigs their dad sets up. David's especially sour on playing outside in December.
"Oh my god," he says, rolling his eyes. "You're putting a piece of metal to your lips. It's always better to be inside."
David Greenberg complains about it, but he does play outside -- with the family, and on his own. A while a go he signed up with the VFW to play taps at veterans' funerals. There aren't enough trumpeters to go around. David says he got paid the first time he played at a funeral.
"So I told them, I'm not going to get paid for this anymore because I feel bad," he says. "So I'm just going to do it for the heck of it, because I feel it's a good thing to do."
The quartet plays another tune. It's a complex, haunting arrangement of "The Huron Carol". A small girl and her mother stand a few feet away, listening.
Bob Greenberg says it's a blast playing music with his kids.
"You keep on telling your kids that there was a simpler time when you were young, and you did caroling around the neighborhoods," he says. "You know, it's not there anymore."
He says his family is "fortunate," and that's another reason they play for donations.
"We are definitely not made of money," he says. "But we could be so much worse off. I just figure if I can give to people that really need it worse than I do, then I've done something good."
Bob Greenberg and his wife Carrie coordinate a summer music camp. More than 300 kids from Minnesota and Wisconsin some to Superior for the camp. Fifty of those kids get to come without paying tuition. Last year, the camp was short nearly $2000, so Bob Greenberg paid the difference out of the salary he gets as a nurse.
Last year, when the Greenbergs were playing outside a shopping mall, a woman walked up and gave Bob Greenberg a pair of gloves. He still carries the gloves in his tuba case. He says they'll come in handy later this month, when he and his sons are back in the shopping mall parking lot playing at the Salvation Army kettle.