Nice post, I'm looking forward for the next one. Meanwhile I'll give my 2 cents.
The main problem in analyzing tonal music is that we mainly listen to relations between chords. For instance, in the following progression in C major, A major functions as a dominant of D (D is the dominant of G and G is the dominant of C):
C A D G C.
OTOH, in the following progression the same A is the subdominant of E:
E A B E.
This means that if a song modulates or there's a tonicization [1] the same chord will have different tonal functions and we'll listen to it differently. Just counting a chord in a song may not be enough if they have different functions.
The number of repetitions also matters. Tonally, the progressions C | C | C | G | G and C | G | C | G are the same as C | G. Is he eliminating repetitions in the analysis?
About using A major in C; you can use it as a dominant of D (see my 1st example) or as a chromatic mediant [2] in C major. Of course, in modern music you can use anything you want, but these two are the most common uses.
And, naturally, the types of chords used will vary according to the music style.
The grandparent is talking about modulation within a song. Unless they normalized each section of each song to C without saying so, modulation is still an issue. For instance (though I greatly doubt it's on their list) Jethro Tull's "The Whistler" has one key for the verse, a different one for the chorus, and yet another for the whistle solo...
Right, all of the songs were normalized to C, which exactly the point. At Hooktheory.com you can examine all of the songs in relative notation (i.e. I IV V in place of C F G) which makes it easier to compare chord progressions without having to bother with their respective keys.
The main problem in analyzing tonal music is that we mainly listen to relations between chords. For instance, in the following progression in C major, A major functions as a dominant of D (D is the dominant of G and G is the dominant of C):
OTOH, in the following progression the same A is the subdominant of E: This means that if a song modulates or there's a tonicization [1] the same chord will have different tonal functions and we'll listen to it differently. Just counting a chord in a song may not be enough if they have different functions.The number of repetitions also matters. Tonally, the progressions C | C | C | G | G and C | G | C | G are the same as C | G. Is he eliminating repetitions in the analysis?
About using A major in C; you can use it as a dominant of D (see my 1st example) or as a chromatic mediant [2] in C major. Of course, in modern music you can use anything you want, but these two are the most common uses.
And, naturally, the types of chords used will vary according to the music style.
[1] http://en.wikipedia.org/wiki/Tonicization [2] http://en.wikipedia.org/wiki/Chromatic_mediant