I have flown Lufthansa, KLM, Air France, and British Airways carrying music gear. The only bad experience was on Air France where the headstock of a guitar was broken even though it was in a hard case padded with towels wrapped around the neck and headstock. They refused to pay any damages. Lufthansa and KLM are both outstanding airlines and would be among my top preferences. I fly Delta a lot and highly recommend them, also.