You may carry one (1) musical instrument in addition to 1 carry-on and 1 personal item through the screening checkpoint. This is a TSA Screening Policy. Airlines may or may not allow the additional carry-on item on their aircraft. Please check with your airline before you arrive at the airport.
Security officers must x-ray or physically screen your instrument before it can be transported on an aircraft.
Security officers will handle musical instruments very carefully and will allow you to be as involved as possible in any physical screening.
If security officers cannot clear the instrument through the security checkpoint as a carry-on item, you should transport the instrument and checked baggage instead.