CONCORD, N.H. -- The U.S. Fish and Wildlife Service is looking for a little harmony over rules used to enforce a ban on ivory that ended up snagging a pair of teenage bagpipers at the Canadian border.

In August, Campbell Webster and Eryk Bean of New Hampshire were returning from a competition in Canada when their pipes were taken. The reason: They contained small pieces of ivory. The U.S. prohibits importing ivory taken after 1976.

Even though the boys had certificates showing the bagpipes' ivory was harvested before 1976, a combination of required paperwork and the type of border crossing they used caused U.S. Customs and Border Protection to seize the pipes at Highgate Springs, Vermont. The teenagers contacted New Hampshire's congressional delegation, their predicament sparked an online petition and they shelled out $576 in extra fees to get their pipes back the next day, just in time to fly to Scotland for the world championships, where they placed ninth.

Craig Hoover, chief of the wildlife trade and conservation branch in the Fish and Wildlife Service's division of management authority and international affairs, said this week that the ivory ban will remain in place but the new rule will make accommodations for things like musical instruments.

"The criteria caused some concern," Hoover said. "We met with the League of American Orchestras and based on those concerns, we made some changes."

Hoover said he couldn't provide specifics of the rule changes because they're still making their way through other government agencies that will need to weigh in. Once the new rule is proposed, it will be open to a 60-day public comment period before a final rule is proposed and any decision made, a process that could take several months, Hoover said.

"Our goal is to harmonize our regulations across these various pieces of ivory restrictions," he said.

Musicians will still require a certificate showing the ivory in their instrument was harvested before 1976 but Hoover said the agency will propose specific ways to allow certain activities to continue.

"Particularly those that involve a small amount of ivory," he said.

The agency has already issued about 70 certificates to cart ivory across the border this year, Hoover said.

Campbell Webster, who at 18 is now the youngest professional piper in the states, was relieved at the proposed rule change. He's been playing the bagpipes for 14 years and the 1936 set that was seized belonged to his father, Gordon Webster, who was the 9th Sovereign Piper to her Majesty the Queen of England Elizabeth II.