I remember my grandfather had a parakeet. When I was very young and we would visit during the holidays, he could make the parakeet sing Christmas songs. He would hold a lit candle under the birds right foot and the bird would start singing "Oh little town of Bethlehem..." and then he would move the lit candle to under the left foot and the bird, without skipping a beat, would go right into, "Joy to the world the Lord has come...". He got the biggest kick out of showing off his special bird.
Well, one time, when my grandfather left the room to go to the bathroom, he went to the bathroom a lot, I held the candle right between both feet of the bird to see which song he would sing. The bird immediately started singing, "Chestnuts roasting on an open fire...", no lie.