The Zebra Song

When I put Isaiah to bed I usually sing him a few songs while rocking him. This is something we've been doing for the past 6 months or so. Initially I would sing 3 or 4 songs in order and put him in bed, including Twinkle Twinkle Little Star, Goodnight Isaiah (tune of Goodnight Ladies from Music Man). After he was used to that, he began requesting songs. At first, it was ones that he knew from me singing them to him. Then, he began making up titles to songs he wanted me to sing. He would look around his room, saying "ummm... which song?" Then, he would point at something in his room and say "window song" or "bear song." Kind of hard to make something up like that! Then, he began requesting the zebra song, looking at his Bounce and Spin Zebra.
Somehow, I figured there has to be zebras on a farm somewhere in the world. So, I sang "Old MacDonald Had a Farm" with a zebra. I think they make some noise, like "breh"... could be wrong... Now this is a nightly request - the "Zebra Song." He's going to have his teachers baffled when he calls "Old MacDonald" the Zebra Song sometime in the future!