I've been on a flight with incessant really loud singing. The whole flight. Could not get the person to stop, even though it was a 6am departure. They started before we even left the gate and kept going until we landed. Just ridiculous. I could tell I was not nearly the only one sick of it, but figured telling them to knock it off might not end well. Because it was the flight attendant and I reminded myself why I hate flying Southwest.