Along the way there's mention of modal mixture and modal mutation; the concept of the plagal cascade (i.e. C-G-D-A-E chord progression that makes up the song); and blues tonality with some comments from Ethan Hein, which, of course, you can get to by way of Ethan Hein's link to Adam Neely's discussion.
Now something that's fun about Neely's presentation is that he points out that plagal cascades are a morphological outworking of the tuning of the guitar. To put that in more colloquial terms, when guitarists let their fingers do the walking they tend to let their fingers be guided by shifts of consecutive fourths that let them use as many open chord root movement shifts as possible. In Baroque keyboard-based music, by contrast, circle of fifth chain progressions were the norm.
Thus "Fly Me to The Moon" and "I Will Survive" use chains of circle progressions (variants of the V-I/V-i/vii-I) in contrast to guitar music that tends to use plagal cascades a la "Hey Joe". Depending on how short the plagal cascade loop is D-A-E could be just short enough to define one of the more prevalent chord loops in rock and blues.
