Pop Standards Puns

My sister posted about loving my little ponies, and we got on the topic of rainbow horse poop jokes. My dad just pops in with this:

Dad - I can't think of one right now. I do, however, have a poem that is somewhat related: (first assume standard high-class poetry recitation position; head high, chest out, hands clasped behind back, heels together, toes @ 180 degrees, knees slightly bent): "In days of old, when knights were bold, and toilets weren't invented; they left their load beside the road, and went away contented."