Let's be specific - which 20 verse ballad, do you feel unable to perform in the present climate?
in what style do you propose singing it?

How long do you think it will take in its entirety and do you feel committed enough to the piece to know the words, and have you reheardsed it enough to have worked out how to engage your listeners interest?

i think you should ask yourself these questions whether its Tam Linn or American Pie.