“Short A Couple A’ Bob” by Gaelic Storm. I couldn’t find a YouTube link to share, but it’ all about being poor. It’s got a lot of Irish slang throughout, so it might be hard to pick up on to a non-Irish audience.
My two:
“Dead Presidents” – Classic blues, written by Willie Dixon, sung by many
(also, evidently the title of a Jay-Z song. A rapper singing about money? Who would have thought)
“I Aint’ Broke, But I’m Badly Bent” – Classic bluegrass, covered by everyone.
“Richard Corey”, as done by Simon and Garfunkle, is about a rich man for whom money and all it’s trappings couldn’t buy happiness.
:smack: