Lydia LOVES the song "the Itsy Bitsy Spider" and for being sixteen-months, I think she does quite well with the motions. You can't really hear her "words" in the clip, but they something like this: "Eeee beeee, DOWN, eeee beee, YAY!!!!! (Clapping)"
The second clip is Joshua singing for her. He's really sweet about this (usually) and has started insisting that James/I can't sing along, he wants to do it for her by himself.
In general they're playing together more and he's pretty sweet, but we definitely still have our moments (days) where they're out to get each other. Or, more accurately, Joshua's out to get Lydia--she still worships the ground he walks on.