just wanted to pass along some info related to travel with an instrument...
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.
Not sure if it was just that one airline I was on, but the last time I traveled with my anvil case, I could not fit it under the seat in front of me. I just sort of hid the fact that it wasn't fitting very well, and made like my knee in my face was really comfortable, but I wasn't going to put it anywhere else (not sure if it fits in overhead).