Schoolhouse Rock! (Heard once in "Unpack Your Adjectives" and "The Body Machine".)
Sesame Street (Heard once in a high pitch in "Big Bird and Snuffy Bumper: Sheep" and in a normal pitch in the "Mad Scientist Invents a Capital H" cartoon.)
Sheep in the Big City (Heard once in reverse in "Fleeced to Meet You". It is also used in "An Officer and a Gentlelamb".)