Let me try this again; I think I started this all wrong.

My friend wants to do a OMB type of product, but he doesn't have any instrumental ability. He's a great singer and does a fine job of conversing with the crowds. He wants to focus on a Polish-American style, but needs backing music. He can easily do a capella, but I feel some sort of MIDI, mp3 setup would be better. Looking for music source suggestions...