At the only home we've ever sold, we simply played softer tracks from our personal collection. It included purely instrumental pieces, as well as songs by the likes of Leonard Cohen. We can report that the sale went swimmingly (and that was in 2009 - not exactly the year to be selling real estate!). We don't necessarily attribute it to the music, but we do think it payed to simply show the home as a place that was honest, loved, and well cared-for.
What music would you recommend to sell a house to? Anything you think is sure to put the buyers in that home-buying sort of mood? Or do you agree that no music is always the way to go?