An increasingly forgetful grandparent from a child's point of view: Big, hearty Grandpa amuses the kids with his songs, especially a silly one he's made up that pokes fun at his own performances. When it turns out that his own song is one of the things he no longer remembers, the family's response is cheery and understanding. Johnston's poignantly understated text is creatively counterpointed, in Sneed's fine debut, with ebullient watercolors where Grandpa's outsize girth is echoed in funhouse- mirror perspectives. Warmly evocative. (Picture book. 4-8)