Read this strip at gocomics.com.
A character is needed for Charlie Brown to talk with sometimes, and the character chosen depends on what role he must play in the strip. If it's an equal then it'll be Shermy, if it's something that involves playing or social matters it'll be Patty. If it involves throwing him out of her house then Violet.
Already, Schroeder doesn't get much play outside of his piano, but he works here because he's a little younger than Charlie Brown and thus apt to ask questions regarding the shape of the sun. Lucy could also perhaps have filled the role, although it won't be long before her willful ignorance of such matters becomes prominent.
This is exactly the kind of strip that Linus would be in, if he were old enough to talk yet.
