Keep On The Sunny Side
(Source: "The Kids' Campfire Book", Jane Drake and Ann Love, Kids Can Press, 1996.)

Chorus:

Keep on the sunny side, always on the sunny side,

Keep on the sunny side of life, YEE-HAW!

You will feel no pain as we drive you all insane, so

Keep on the sunny side of life!

(between choruses, do a series of knock-knock jokes, like the following:)

Leader: Knock knock!

All: Who's there?

Leader: Ether!

All: Ether who?

Leader: The Ether Bunny! HA HA HA HA...

Leader: Knock knock!

All: Who's there?

Leader: Nother!

All: Nother who?

Leader: Nother Ether Bunny! HA HA HA HA...

Leader: Knock knock!

All: Who's there?

Leader: Stella!

All: Stella who?

Leader: Stella Nother Ether Bunny! HA HA HA HA...

Leader: Knock knock!

All: Who's there?

Leader: Cargo!

All: Cargo who?

Leader: Cargo beep beep and run over all the Ether Bunnies! BOO HOO HOO...

Leader: Knock knock!

All: Who's there?

Leader: Boo!

All: Boo who?

Leader: Don't cry, the Ether Bunny will be back next year! YAY!

Thanks to Karen Dawson for this great ending:

Leader: Knock, Knock!

All: Who's there?

Leader: Ya!

All: Ya who?

Leader: See, I told you he'd be back! HA HA HA HA!!