From: egras@ohstpy.mps.ohio-state.edu
Newsgroups: alt.guitar
Subject: Re: chord theory
Date: 9 Oct 92 18:58:15 GMT

In article <1992Oct9.154609.17203@athena.cs.uga.edu>, barrett@athena.cs.uga.edu (Richard Barrett) writes:
> From RBARRETT@uga.cc.uga.edu Fri Oct  9 08:39:04 1992
> To: barrett@athena.cs.uga.edu
> 
> Could someone help me out with theory on chord progression.  I know all about t
> he I-IV-V but now I am ready for other worlds of music.
> 
> What chords are used in a certain key?
> What chords sound good togther?
> What about resolution?
> What about moving to a different key within a progression?...etc.


In classical music, there are very strict rules for all of the above.

1)  In Major: the diatonic chords (i.e. chords appearing naturally in a key
such that the chords don't need any sharps or flats) are
	I ii iii IV V vi vii'  ( where caps are major, lower case are minor,
				 and the apostrophe means diminished)

    In minor:  the diatonic chords are:
	i ii' III iv V VI vii' (remember in minor keys the 7th note of the 
				scale is raised a half step. e.g. in a minor
				you have a g# rather than a g natural)

2)  In classical music, there is a chart indicating which chords can follow
    which and which chords can precede which.

	In major:                                  +---
                                 /--------------\     /                  
		iii---+ vi ---+ IV ---+ vii' ---+ I --
		        /       ii       V
        	       /________________/

	I know this is hard to read. Sorry.  ---+ is arrow whose direction
	can't be reversed.  If the + is missing either direction is ok.
	Note,  I can go to anything.  IV goes to I, but ii does not. 
	Top chords can go to chord below but bottom can't go up.
	vi goes to V and V goes to vi.  vi does not go to vii' or vice versa.
	The only way to get to iii is from I (iii is not common in classical).
        ii goes to either vii' or V. V goes to either vi or I.
        IV can go to ii, vii', V or I.

	In minor:
                                                               +---
                                          /-----------------\     /
		VII ---+ III ---+ VI ---+ iv  ---+ vii' ---+ i ---
                                  /       ii'       V
                                 /_________________/

	Note in minor I included VII which I didn't include in the diatonic
	chords in 1) above.  The reason is that in minor there are more 
	available chords depending if you are in natural minor, harmonic minor,
	or melodic minor.  In 1) I assumed harmonic which is most common.


3) For resolution there are different types of cadences.  
	Perfect Authentic  V ---+ I both in root position.  Tonic in top voice.
	Imperfect Authentic V ---+ I any deviation of perfect
                          or vii' ---+ I
	Plagal IV ---+ I
	Half  ? ---+ V  where ? is any chord allowed to go to V.

Note:  for minor just substitute i for I.

4) You can modulate to any key but some are smoother than others.
   Closely related keys differ by one sharp or flat at most.  These are the
   smoothest.  e.g. G,F,a,e,d are all closely related to C.  There are many 
   more ways to modulate but this is the simplest.


I hope this helps.  There is MUCH more to the theory than this.  You might want
to take a music theory class some day.  If you can't tell,  I've taken several.


later,

BrianE
Newsgroups: alt.guitar