One will start and if the other is home .. will join in. Without a doubt! I love watching these two play the piano together and the special bond they have. What's even more special to me is the special bond they have, playing the piano, is that it's the piano I have had since I was Addison's age and learned to play on. I'm so thankful my parents kept this old, out of tune piano all these years! I am speechless when it comes to my gratitude for Heath and the loving father he is.