keeping it in they key of C, starting from my fixed post in the T&T forum
Tone Deft wrote:ugh, take two for redemption. this stuff really isn't all that difficult. DO ANY PLAYERS HAVE TIPS FOR THE RIGHT HAND VS LEFT HAND PLAYING?

only look at the white notes.
take them three at a time, separated by one note, like
C E G = C
D F A = Dm
E G B = Em
F A C = F
G B D = G
A C E = Am
B D F = Bdim
very simple. those are all the 3 note chords in C.
the 4 note chords (the 7th chords) are the same with another note tacked on
C E G A = C7
D F A B = Dm7
E G B C = Em7
F A C D = F7
G B D E = Gdom7
A C E F = Am7
B D F G = Bm7b5
you could tell someone you're playing a I - V - VI -IV in C
* and they know all they need to know to play along with you.
I in C = C E G = i iii v in the C major scale = C major chord
II in C = D F A = i biii v in the D major scale (D E F# G A B C#) = D minor chord
III in C = E G B = i biii v in the E major scale (E F# G# A B C# D#) = E chord
IV in C = F A C = i iii v in the F major scale (F G A Bb C D E) = F major chord
V in C = G B D = i iii v in the G major scale (G A B C D E F#) = G major chord
VI in C = A C E = i biii v in the A major scale (A B C# D E F# G#) = A minor chord
VII in C = B D F = i in the B major scale (B C# D# E F# G# A#) = B diminished chord (diminished chords are characterised by a flat 5th aka bv or b5. FWIW I tend to use numbers instead of lower case roman numerals, I believe both are accepted as standard notation.)
(notice how each chord is still every other note from its major scale? it's the same technique applied over and over again, 'stacking' every other note. as giggedy pointed out in the T&T thread, it's 'stacking thirds.' check his web site for info on that or ask here.)
chords and scales are basically the same thing. chords are notes played at once, scales (and keys) and groups of notes to choose from. with both, notes are in lower case, chords are upper case.
a major chord is ALWAYS the i iii v of the major scale.
a minor chord is ALWAYS the i biii v of a major scale.
major scales are ALWAYS i ii iii iv v vi vii
minor scales always have a biii in them (there are a few flavors of minor scales.)
giggedy pointed to his web site where this is laid out further.
http://forum.ableton.com/viewtopic.php?p=893589#p893589
hth, I'll keep it short so others can fill in or you can ask more questions, it's real easy to go overboard with this stuff very quickly.
*that's the chord progression to the "4 chords, 30 songs" video that went around. good lessons to be learned there.
http://www.youtube.com/watch?v=qHBVnMf2t7w
all those songs use I VI V IV they just change keys. so, by now I should be able to tell you to play I VI V IV in F# and you'll know which chords to play, which order to play them in and which notes are in those chords. it will also tell you how you can solo over the song.
this is REALLY easy for guitar players, a little more difficult to piano players.