Once inside, the thieves apparently made a beeline for the shop's most expensive guitars, which typically retail at between $3,000 and $8,000.
"We don't know how much they knew or if they were just turning over the price tags," Winter said.
The thieves also dumped all the trash from the shop's garbage cans onto the floor and apparently filled the cans with a variety of smaller, less expensive merchandise like straps, strings and tuners, he said.
Many of the estimated 40 guitars stolen were speciality and handmade instruments that will take up to a year to replace, Winter said.
"They're all really unique," he said. "They're all very expensive."
Customers, he said, have used social media to spread the word of the burglary and to warn others to be on the lookout for the missing merchandise.
"It's just going to make these instruments harder and harder to sell," Winter said, noting that someone approached him with a tip that the thieves were heading to Arizona with the guitars.
Salt Lake City police Detective Mike Hamideh said the stolen items have also been registered in a national crime database.
"[There's] a very good likelihood we'll get these items back," Hamideh said.
He said police are also offering a reward for information as part of the department's Tips for Cash program.
Anyone with information is asked to call police at 801-799-3000.