Unfortunately Qantas changed the hand luggage regulations last year. Pax can carry two "domestic size" bags OR one "international size" bag. Yes guitars are allowed, but only in soft carry case. Due to this years change to only one flight attendant doing all the boarding, hand luggage is often not sighted. 7 kilos is maximum weight allowed, but there are no scales at the departure lounges to weigh anything. There is now an added problem that the new 737-800's have smaller overhead lockers, and on full flts not all the bags fit and must be removed!