There's an essay about Chappell online which discusses the scene in the book:

'So Jess and his sister Mitzi have a picnic, inviting all the good Green Valley folk, serving plenty of food and providing the music of the New Briar Rose Ramblers (Aunt Sam's reconstituted band). The music is fine and the food delicious, and when the festivities come to a close, Joe Robert reads his father's "tongue in cheek" will (which gives him the last laugh at the school board, the paper company, and the religious hypocrites and sundry mean folk of the valley). The will puts many of the events and most of the villains of the past three Kirkman books in fine cosmic, as well as comic, perspective. Then Jess does the only "fair" thing he can think of—"draws names" to see who will host their mom and dad in eternity, though his own good "will" has already rigged the drawing so that, appropriately, the down-to-earth and simple Irelands win Annie Barbara and Joe Robert. Afterward, as the community listens to the New Briar Rose Ramblers' rendition of "Look Back All the Green Valley," Harley the mandolin player voices the sentiment that Chappell has expressed in each of the previous Kirkman books--"It's the songs that keep us alive--or keep the life worth living, anyhow" '

:-)