i truly believe that art transforms a space. a room is not complete without it. but i also know not everyone feels this way. so here are some examples of living rooms, to convert you to an art believer.
this room would be nothing without that colorful piece on the fireplace. it ties absolutely everything together. go ahead, cover it in the picture… the room falls apart. 
how about this room? (it is madeline weinrib’s living room). it would not be nearly as pulled together if it werent for those two black and whites (in a gold frame, my favorite). they bring everything together.
my last example (i could go on for days), the piece in the corner completely anchors the entire room. it pulls it all together with its darkness.
*sources: apartment therapy, elle decor and bazaar of serendipity