"You would like to play with Donny and Duncan." So the narrator for Playing Together confidently tells us, and we have no reason to doubt him. But as the minutes pass it becomes clear that he may have been overselling Donny and Duncan just a bit.
Donny, as it turns out, has trouble navigating life, from the smallest things (he's confused and frightened by the rules posted at a public pool) to larger problems, including the question of evil (his favorable reaction to aquatic clowns makes it clear that his moral compass is broken and he may even be a dangerous psychopath.)
Duncan tries, he really does, to curb Donny's dangerous habit of clinging to every stick he finds like a lab monkey clings to his wire mother, but Donny is too far gone, and Duncan's helplessness and rage is beginning to show.
But what makes it all work is the constant, tuneless piano noodling. Because of it, the narrator wins in the end: Kevin, Mike and Bill would like to play with Donny and Duncan.