David Gilmour has a knack for always playing exactly the note that the listener
expects him to play. I probably sound like I'm saying "his playing
is predictable", but I mean it in a good way.

Its like those studies where they morph together images of thousands of faces
to produce an "average" face that is actually more beautiful than any real
person, not "average" or "ordinary" looking in the usual sense of the words.

Compare the Jargon file entries for "canonical" and "vanilla":

http://catb.org/esr/jargon/html/entry/canonical.html
http://catb.org/esr/jargon/html/entry/vanilla.html

Gilmour's playing is canonical, not vanilla.