I agree. You can’t go wrong with these four: Frank Sinatra. Nat King Cole. Bing Crosby. Burl Ives.
I have to disagree with you on Nat King Cole. I was a part time DJ in college and I worked several shifts over Christmas so the regular staff could have some time off. Instead of our regular programming, we played wall to wall Christmas music. Over twenty years later, Nat King Cole’s version of “O Tannenbaum” (in German) is still seared into my brain. The man clearly didn’t know the German language and absolutely butchered that song. It was horrible.
Yep, that's all good. I have my Pandora app open and playing the Bing Crosby holiday channel. Naturally the "music genome project" casts a wider net, but so far it's stayed with the traditional performers.