Chicago blues guitarist Nick Moss has a number of cherished guitars, but none more prized than his cherry 1966 Gibson ES-345, a beautiful axe that Moss purchased in a Chicago music store and took out on the road for several years before retiring it. (“I was just so paranoid about something happening to it,” he says.)

The guitar itself is remarkable enough, but the story of how Moss acquired it isn’t bad either. And it’s not only a great guitar memory, but also a cautionary tale for owners of music stores: Don’t yell at your employees—especially if they’re going to be selling vintage instruments in your absence.

“I had seen an ad for the guitar, and I came in specifically to look at it,” Moss recalls. “I had wanted a 345. When I walked in, the owner of the store was yelling at the salesman, and he was making no effort to keep it cool in front of the customer. The owner just decided he was going to play big man, so he kept screaming at the guy about something. The last thing he said before leaving was, ‘I’m going out to lunch now. Don’t bother me!’ And then he left.”

The salesman—after being dressed down for 20 minutes—finally offered to help Moss. He plugged in the 345, and it didn’t take Moss long to realize that he was holding a guitar that he just had to own. “It was one of those things,” Moss says. “I kind of know, just by looking at a guitar sometimes, that as soon as I take it off the wall and it hits my hands that I’ve gotta have it—even before I plug it in. It was like that for this guitar. I plugged it in, and right away I was like, ‘Oh yeah, this is it.’”

Moss quickly made up his mind. “I’ll take it,” he told the salesman. “I want this one.”

There was just one problem. The salesman looked up the price and informed Moss that the guitar would cost $2,600. Moss had carried $1,800 into the store.

“Twenty-six hundred? In your ad, you’ve got $1,795,” Moss pleaded.

The salesman viewed the advertisement that Moss had carried into the store and showed the bluesman the error of his ways: There were actually two other ES-345 models for sale in addition to the ’66, and Moss had erroneously connected the wrong price to the guitar he wanted.

“So the guy gets on the phone, and he calls up his boss,” Moss remembers. “And I can hear the boss on the other end because he’s so loud: ‘I told you not to bother me! I’m at lunch!’ The salesman just says, ‘Hey, I’ve gotta talk to you. There’s a guy here in the store, and he wants to buy that ’66 ES-345.’ And the owner is like, ‘So what’s the problem? Just sell it to him.’

“The problem is that you mistagged it,” the salesman told the store owner.

“As he was on the phone talking to his boss, the guy just kind of looked up at me, and I could see this glint of a smile on his face,” Moss recalls. “Turns out that he was explaining to the owner that there was a tag on the guitar that I wanted for $1,795—and that it was in his handwriting. He just put it all on the boss.

“There was dead silence on the phone,” Moss continues. “Then I hear the salesman say, ‘Yeah, he’s got cash.’ He hangs up the phone and says to me, ‘It’s yours. Eighteen-hundred bucks.’”

Moss says he needs to keep his benefactor’s identity a secret. “The guy still works there,” Moss says. “Every time I’ve gone in there since, we’ve sort of had this unspoken thing: He remembers me, I remember him, and we both remember what went down on that day. It was a funny thing.”