Quote from Quack
One mistake new timid singers make is to learn the most long and difficult songs they can find (or that is how is seems to a listener), with no chorus or joining in bits. All this does is expose any weaknesses they may have, including the fact that the more words, the greater chance of forgetting one. I am a great believer in keeping it short with plenty of chorus.
Unquote

I fully agree there Geoff.