A new federal rule is giving some musicians pause about traveling internationally with their instruments, according to WQXR. The regulation, which went into effect in February, bans musical instruments containing ivory - even those containing tiny amounts of ivory, like that on the tip of a violin bow - from entering the U.S., unless documentation can prove that the instruments were purchased before 1976. The rule came about in response to an increase  in elephant poaching in Africa. Some U.S. musicians worry that, once they've left the U.S. with instruments that contain ivory, their instruments could be confiscated upon returning to the U.S. String instrument bow maker Yung Chin is designing synthetic tips that can replace ivory tips on some bows.  But because the synthetic tips look like ivory tips, there's no guarantee synthetic bow tips will prevent the kind of instrument seizures that worry some musicians. Read more: Ivory Band Good for Elephants, a Headache for Musicians (WQXR)