Andy Williams was a real fixture on TV in the 1960s. His "Andy Williams Show" ran from 1962-1967...and was rebooted from 1969-1971. And, in the years before and after, Williams returned to TV for various specials. He was a VERY busy man.
I found his 1966 Christmas special on YouTube, but it's not exactly his Christmas special but is a Christmassy episode of "The Andy Williams Show". The following year, he had the stand-alone "Andy Williams Christmas Special"...and it's easy to confuse the two.
In this TV show, Andy brings out his family...his wife and two young kids, his parents as well as his three brothers. Along with them, the Osmonds appear...something they often did on Williams' shows.
Most of the show is like a series of music videos strung together...without a lot other than singing and a scene where everyone gets together and acts like it's Christmas at the Williams mansion.
What I liked most was seeing and hearing Williams with his brothers. I had no idea that they were a popular singing group and later, Andy stepped out on his own and became a huge star. This would seem to explain Williams' having the Osmonds on his show through the years...their story is pretty similar as Andy and Donnie were the youngest in the group and both left to greater fame as solo acts. The Williams brothers singing was great.
I also liked the usual Andy Williams solo Christmas tunes. As for the Osmonds, they sang a medley of Disney music which held little interest for me.
What was also interesting was seeing his family...especially his wife (and later ex-wife) Claudine Longet...whose off-screen exploits in the year following their divorce is the stuff of legends.
Overall, a very interesting and enjoyable show...the sort of thing they definitely don't make any more.