Okay, this one is amazing. Recall that a producer named Ross Bagdasarian broke into the pop music fray in 1958 under the pseudonym David Seville with a novelty act called the Chipmunks. The trio, whose voices were actually his own, were recorded at half speed and then replayed at double speed, making them seem an octave higher. The resulting song, Christmas Don't be Late, captured the #1 spot on the charts in December 1958. Incidentally, the Chipmunks were named after the top executives of Liberty Records, for whom he was under contract.
They culminated with a live marionette appearance on Ed Sullivan that December and set the stage for an animated series on CBS for the 1961-62 season. Here the world first saw them in their animated form, and it was here that this animated version of the song was first aired.
From Christmas, 1961, Alvin and the Chipmunks: