As I recently posted on another thread, I heard "The Ballad of John Williams" sung in a pub in Dublin just a few weeks ago. It's a great piece of very straightforward songwriting by Johnny McEvoy as it encompasses the reasons why people wanted to leave Ireland with high hopes of a better life in America, and while it never actually mentions the Titanic by name, the third verse leaves you in no doubt that that's what it's all about.
Here's a link to Johnny singing it and the lyrics (very slightly different from the video) are on a thread - "The Ballad of John Williams"
http://www.youtube.com/watch?v=jOX5wIeKEcw