
It occurs on a couple of the solo guitar tracks found on what was the second side of the original vinyl LP. 40+ years ago, this was an amazing effect and was intended to sound pretty.
Today, I'll admit it sounds dated and is rather annoying, However it's only used on tracks 11 & 12 (and the intro to to track 9) and has nothing to do with mastering and isn't a defect - this is what Chet intended.
The rest of the acoustic tracks and all the electric guitar tracks (what was vinyl side 1) are free of it and sound fantastic. One of the most "Chistmas-y" records ever made....
There are noticible "wobbles" in the sound, otherwise
the playing of Chet is great, he plays solo classical on the songs at the end of CD which is real nice.