Hi Yazmeen, yes I have seen the Bing and David pairing many times before. While I like much of what David Bowie puts out there musically, in my opinion, his voice quality is not superior to Clay's in any way. They have different styles and range of notes, so of course Clay wouldn't sound like David Bowie, nor should he or be compared vocally. I didn't feel Clay was off tempo or off key at all. (It is harder to sing with an "image" than it is to sing with someone in person).
Although I would have liked to have heard Clay sing his own song during the special (I thought the special as a whole was not very appealing), I think it must have been flattering to have been chosen to be paired with the great Bing Crosby. Perhaps, another one of his songs, such as "White Christmas" could have been used instead of "Drummer Boy", but we "Clay" fans take what we can get................ 42