The rule requires that each U.S. carrier subject to this regulation allow a passenger to carry into the cabin and stow a small musical instrument, such as a violin or a guitar, in a suitable baggage compartment, such as the overhead bin or a closet, or under the seats, in accordance with FAA safety regulations and the carrier’s FAA-approved carry-on baggage program.

Carriers must allow passengers to stow their small musical instruments in an approved stowage area in the cabin if at the time the passenger boards the aircraft such stowage space is available. Under the rule, musical instruments as carry-on items are treated no differently from other carry-on items and the stowage space should be made available for all carry-on items on a “first come, first served” basis. Carriers are not required to give musical instruments priority over other carry-on baggage, therefore passengers traveling with musical instruments may want to buy the pre-boarding option offered by many carriers to ensure that space will be available for them to safely stow their instruments in the cabin.

For some musical instruments that are too large to fit in the cabin stowage areas described in the carrier’s FAA-approved carry-on baggage program (e.g., an overhead bin or under a seat), it is sometimes possible to secure them to a seat as “seat baggage” or “cargo in passenger cabin.” Carriers are required to carry large musical instruments in the cabin if the passenger wishing to carry the instrument in the aircraft cabin has purchased an additional seat to accommodate the instrument and the instrument is contained in a case or cover to avoid injury to other passengers, the weight of the instrument does not exceed 165 pounds or applicable weight restrictions for the aircraft, and the instrument can be stowed in accordance with the requirements for carriage of carry-on baggage or cargo established by the FAA. Carriers are not required to provide for this process in their carry-on baggage programs; however the Department encourages carriers that do not currently allow such stowage to amend their programs to allow it, provided that all safety requirements are met.

- See more at: https://www.transportation.gov/briefing-...h.1Z3vIjob.dpuf


https://www.transportation.gov/airconsumer/air-travel-musical-instruments