Abby, you're more than have way there to figuring it out. You're obviously able to critique your own performance, and that can be a rare quality in some circles. Traditional ballads are not easy fodder for many folks. Same with certain genres of film, theatre etc. I took 3 friends to see "Enfants du Paradis" about 20 years ago. All three walked out, bored stiff!

You don't mention whether you sang other songs as well, and whether they were well received or not. Have you done other songs on different weeks? Did folks like 'em? I get the feeling that if you had a pitch problem, you'd know. You don't mention stumbling over the words (it is a story song) or making false starts. If you had a clean slate in those areas, I think the problem lay with the audience. Next time you could do something easier for the majority to digest OR you could sing the ballad again! And AGAIN!

Best of luck

Rick