guitarguy Wrote:
-------------------------------------------------------
> > Tonic = I, vi, iii
> > Dominant = V, vii
> > Subdominant (or pre-dominant) = IV, ii
>
>
> Okay the iii acting as a rootless tonic I
> understand, so why is the vi acting in the tonic
> family???
Like I said, you can see it as a rootless I6 chord. Like iii, it has two notes in common with I.
Admittedly, there is (IMO) something a little odd about this theory.
In key of C major, Em and Am are both supposedly equally capable of standing for C - not totally, but replacing C in a chord sequence. IOW, ending a song on Em or Am won't sound as "finished" as ending on C, so C is still the governing tonic. But in the middle of a progression they could work.
F and Dm both have a subdominant function - deviating from I and leading towards V. And vii can replace V, in that both will lead to I.
The two weird things are:
1. Am is also the relative minor tonic. A different key from C major. It may therefore have that implication if replacing C. ("Hold on, are we in A minor now?")
2. In C major, Am and F have different functions. But in F major they have the same function! I.e., Am can stand for F, and
not for C (which is V). Likewise, in key of G, Em will stand for G, not for C (which is IV).
I'm not going to attempt to explain this, except to suggest it may just be another example of vulgarizing a theory principle: expecting it to always apply, whereas in fact there are always nuances and exceptions. ;-)
> > You could even consider "dissolving" the chords
> > themselves, not seeing them as fixed harmonic
> > "modules", and treat the sequence as a group of
> > simultaneous melodies. The song's melody is on
> > top, the bass line is a melody beneath (or can
> be
> > developed melodically - doesn't have to be
> roots
> > all the time). In between, you only need one
> or
> > two other notes to make "inner voices" to
> complete
> > the harmony. Forget about chords altogether
> and
> > (starting from melody and bass) just explore
> what
> > notes sound good together, and how they can
> move
> > with the melody.
>
> My brain exploded
:-).
It's a historical viewpoint, that kind of became fashionable again in jazz.
In the early modal period (broadly speaking) there was no harmony. At the beginning of western music, there was only unison singing (and octaves). Then the perfect intervals (4ths and 5ths) became acceptable. Then - very slowly over a long time - 3rds and 6ths became acceptable ("imperfect consonances" rather than dissonances).
Rather than the "chords" we use now (in what's known as "melody-dominated homophony") there was "polyphony" - many melodies moving at the same time and interacting. The principles of counterpoint were developed to define which intervals could work together and which couldn't. It's an extremely complicated system.
Eventually - I'm simplifying here! - It all got narrowed down to this system of "chords": fixed harmonic blocks with a single melody moving over the top. It was
as if chords were invented as a set of simple harmonic "modules" or "units" that could be slotted together like a machine, to save all that business of freely moving melodies. (Nevertheless, the art and craft of Harmony - as exemplified by Bach's chorales and taught as SATB 4-part harmony - retains counterpoint principles, and is more complex and rule-bound than how we use chords today in popular music.)
Stevel may be along shortly to correct all this and expand on it. :-)
It was modal jazz that decided it was time to break those chord structures all down, and dissolve them into scales. They didn't quite go back to polyphony, however. Polyphony (of a kind) in jazz had already been done: in the early jazz of New Orleans, where the lead instruments would all improvise melodically over one another.