1. The hard case is needed so it doesn't get crushed in the overhead bin or in the cupboard.

2. Inquire at the customer service desk or check in counter prior to the flight for assistance. Some airlines require a sticker indicating pre-approval by "the airline" so the gate agent and flight attendants don't reject it fromn the cabin as oversize.

3. I have seen various trip reports on Flyertalk describing that guitars have been permitted even though they took up most of an overhead bin.

(Super large instruments like cellos do require a purchased seat to rest in.)

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