This TV ad has been on a few times (It's about buying/wearing a M&S Christmas jumper) and I've discovered the song 'Jump Around' is by House of Pain. Now this is apparently an American rap group from the late 1980's.

What puzzles me is that the lead singer/rapper Everlast has a most convincing and distinctive Lancashire accent, and the song starts with, "Pack it oop, pack it in, let me begin...". He's called Erik Schrody and was born and bred in New York.
What I'd like to know is, where did Everlast get this excellent Lancashire send-up accent? He seems to have more Irish connections than Lancashire.
I would never have guessed he's a New Yorker!
Can anyone enlighten me?