the xmas special

i found the tape in a second hand store- its the one where alvin gives his harmonica to dying boy and spends the rest of the episode making up for it. does anybody remember this? it obviously pre-dates the series, as the animation is different. The animation, as a matter of fact, is done by Chuck Jones (and obviously so), but I can't find a listing for the christmas special anywhere. Anybody have any idea why?