As you should be aware to make full use of this lesson, the triad chords that arise from such a scale, if the starting note is C, are C, Dm, Em, F, G, Am, B dim.

The 7th chords that arise from such a scale (starting again at C) are:

Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bdim7

Of course, these chords (formed from our scale) can be extended further to include 9's, 11's, and 13's. As those notes are included, the specifics of each chord diverge even more (in the same way that at the triad level, both F and G were simple major chords, but at the four note/7th level, the F extended to Fmaj7, while the G extended
to G7).

Now let me explain where we are headed. I want you to develop an ability to play four note chords for ALL chords in the key, with any of the possible notes in the FULLY EXTENDED (i.e., up to the 13th) chord "on top" (highest tone in the chord). Hence, working with C out of the key of C major, we will be able to play four
note C chords where the top note is any of:

C      D     E     F     G      A     B
root  9th   3rd   11th  5th  13th  maj7th

When looked at this way, it becomes relatively clear we are talking about playing varieties of a C chord with any of the notes in the key on top. Another way of organizing this list is by position in the chord instead of in the scale:

C     E    G      B     D     F     A
root  3rd  5th  maj7th  9th  11th  13th

Our approach to forming useful chords will be to put the root of all chords into the bass, and always use the 5th string for this root. We won't be delving into inversions in this lesson. And why use the 5th string? Only one good reason: when playing with
a root on the 5th string, you have "easy access" to the 5th of the chord on the 6th string, same fret (for all but the diminished chord, which as a b5 instead of a normal 5th). Thus, we have convenient access to an alternate bass tone, for creating some bass movement (you've heard the term "alternating bass").

Also, with 4 note chord voicing, we will be forced to be selective about which notes go into the chord (i.e., a full 13th chord has all 7 notes in the key in it!). In general we'll be trying to get the 3rd and 7th, which are most significant in defining the character
or "type" of the chord. As we've already said, we'll always have the root (on the 5th string), or optionally, the 5th (on the 6thstring), in the bass.

We will use a system that will give us, for each of the seven chords
in the key, seven different voicings, where each voicing has a different one of the seven possible notes in the key in the upper voice. Hence, we are going to cover 7x7 = 49 chords. But don't panic (yet!).

Enough talk, let's play.

Our starting point is Cmaj7, the first chord in the key (C major) we are working in, and the first voicing we want is with the ROOT of Cmaj7 (C) as the highest tone, and the ROOT of Cmaj7 on the 5th string. Here's the chord in tab:

    Cmaj7:

   ---  x  ---
   ---  1  ---   C (root)  (1st finger)
   ---  4  ---   B (maj7)  (4th finger)
   ---  2  ---   E (3rd)   (2rd finger)
   ---  3  ---   C (root)  (3nd finger)
   ---  x  ---

This is a nice maj7 voicing (if you ask my opinion). The "adjacent" tones of the maj7 and the root on the 3rd and 2nd strings gives it a nice feel. Note there is no 5th, but it's hardly missed.

Now what we are going to do is, using the same voicing structure, play ALL the chords in the key. That is, we'll use the same root on 5 string, 3rd on 4th string, 7th (or maj7) on 3rd string,and root on 2nd string chord structure, making adjustments based on the specific chord (b3 for minor, 7th for 7th chords, etc..). Hence, the next chord "up" in the key is Dm7, which is:

     Dm7:

   ---  x  ---
   ---  3  ---   D (root)  (1st finger)
   ---  5  ---   C (7th)   (4th finger)
   ---  3  ---   F (b3rd)  (1st finger)
   ---  5  ---   D (root)  (3rd finger)
   ---  x  ---

Note the bar on fret 3. 3rd and 4th fingers can "slide" up from the Cmaj7 chord without repositioning, and vice-versa.The next chord is Em7, and it has the same shape/fingering as Dm7, only two frets higher up (barre is on the 5th fret).

The next chord is Fmaj7, and it has the same shape/fingering as Cmaj7, but with the third finger on the F at the 8th fret of the 5th string, and 1st finger on the F at the 6th fret of the 2nd string. The next chord is G7, and now we have a new shape (but same general "formula" of root-3rd-7-root, 5th to 2nd string). This one is probably familiar to you as a "C7" shape:

   G7:

   ---  x  ---
   ---  8  ---   G (root)  (1st finger)
   --- 10  ---  F (7th)   (4th finger)
   ---  9  ---   B (3rd)   (2nd finger)
   --- 10  ---  G (root)  (3rd finger)
   ---  x  ---

Next is Am7, with the same shape as our other m7 chords, barre on
the 10th fret. Last is Bdim7. The difference between a diminished 7 and a minor is the b5 in the diminished chord. Our chord voicings have no 5th at all, so the shape for our Bdim7 is the same as our m7 chords. In fact, with no b5, you could say we aren't really playing a Bdim7, but let's not quibble. When played in the context of the other
chords in the key, it's a Bdim7. This one has the barre on fret 12 (or no barre at the nut, with the 5th and 3rd strings fretted at fret 2; in this open position, be sure to keep the 1st string quiet!).

Okay, we've now covered all chords in the key of C major, using a voicing that puts the root on top. Next up are all the chords in C major using a 3rd on top.These are easy, because they are familiar to you. Our formula will be root-5th-7th-3rd on the 5th through 2nd strings. This gives us our standard A7 chord shapes. We start with the Cmaj7 played as:

   Cmaj7:

   ---  x  ---
   ---  5  ---   E (3rd)   (4th finger)
   ---  4  ---   B (maj7)  (2nd finger)
   ---  5  ---   G (5th)   (3rd finger)
   ---  3  ---   C (root)  (1st finger)
   ---  x  ---

Familiar, right? I'm going to assume you either know or can work out on your own the rest of the chords in the key using this formula/fingering/chord shape. Note that because we have the 5th in these chords, the Bdim7 IS a different shape from the rest of the minor chords.Now lets drop back to the chord voicings with the 9th on top. These you probably are less familiar with across the board. Our formula for these voicings is root-3rd-7th-9th on strings 5-4-3-2. The first two you probably are familiar with, particularly you jazzer types:

  Cmaj7(9):

   ---  x  ---
   ---  3  ---   D (9th)   (3rd finger)
   ---  4  ---   B (maj7)  (4th finger)
   ---  2  ---   E (3rd)   (1st finger)
   ---  3  ---   C (root)  (2nd finger)
   ---  x  ---

  Dm7(9) (or Dm9) :

   ---  x  ---
   ---  5  ---   E (9th)   (4th finger)
   ---  5  ---   C (7th)   (3rd finger)
   ---  3  ---   F (b3rd)  (1st finger)
   ---  5  ---   D (root)  (2nd finger)
   ---  x  ---

Now we hit a rather interesting and less known chord shape. The Emin7 is the iii chord in the key of C major. We are forming 9 chords within the key, and the 9th of Emin in the key is F, which relative to the Emi chord is a b9. Hence, the chord is:

  Em7(b9)

   ---  x  ---
   ---  6  ---   E (9th)   (2nd finger)
   ---  5  ---   C (7th)   (4th finger)
   ---  5  ---   F (b3rd)  (1st finger)
   ---  7  ---   D (root)  (3rd finger)
   ---  x  ---

The next chord is Fmaj7(9), with the same shape as the Cmaj7(9) chord. The 2nd finger goes on the 8th fret of the 5th string (the F, whaddya know). Next is G9 (or G7(9), either way). This is a familiar chord shape also:

  G9:

   ---  x  ---
   --- 10  ---   A (9th)   (2nd finger)
   --- 10  ---   F (7th)   (1st finger)
   ---  9  ---   B (3rd)   (3rd finger)
   --- 10  ---   G (root)  (4th finger)
   ---  x  ---

Next is Ami9 (or Ami7(9)), with the same shape as Dmi9, with the D bass note on the 10th fret of the 5th string. Next is Bdim7(b9)), with the same same as the Emi9. Why? Because both have b9's! And that does it for four notes voicings with the root on the fifth string and the 9ths (within the key) in the top voice.

So far, we've covered roots in the top voice, 3rds in the top voice, and 9ths in the top voice, for a total of 3*7 = 21 different chords,although again, many have the same "shape" and hence are the same chord structure.

Let's go to fifths. However, I'm now going to speed this up because
you should now have the concept. Once we define a "formula" for
the chord (a particular set of strings and a particular selection
of chord tones to go on each string), you should be able to work out
the fingerings for the entire set of such chords within the key.

So the formula we will use for putting the 5th on top is to use
strings 5-3-2-1, with with root, 7th, 3rd, and 5th on the respective
strings. So for Cmaj7 we have:

   Cmaj7:

   ---  3  ---   G (5th)   (2nd finger)
   ---  5  ---   E (3rd)   (4th finger)
   ---  4  ---   B (maj7)  (3rd finger)
   ---  x  ---                         
   ---  3  ---   C (root)  (1st finger)
   ---  x  ---

My guess is most of you haven't used this chord form before! I'll give you one more (which may be a little more familiar), then, you're on your own with the rest of the 5th on top chords:

  Dm7:

   ---  5  ---   A (5th)   (3rd finger)
   ---  6  ---   F (b3rd)  (4th finger)
   ---  5  ---   C (7th)   (2nd finger)
   ---  x  ---                         
   ---  5  ---   D (root)  (1st finger)
   ---  x  ---

Now work out the rest: Emin7, Fmaj7, G7, Amin7, Bdim7. Which ones have different shapes from the above? G7 and Bdim7.

Moving on...lets cover the chords with the 11th on top. Here we are going to use a kind of funky formula because, well, because I like it and the fingering works out well. Again, we are working on the 5-3-2-1 string set, and the formula is root-7-9-11. No
3rd, no 5th. Now you could probably rename this chord as some bizarre inversion of something or other, but let's not confuse our concept. If you are playing the chords discussed so far in a key (or any other chords in the key), and throw this in, the surrounding music will "fill in" the sense of the chord. In a band situation, the bass will in all likely hood hit the 5th for you at some point and maybe the 3rd too, etcetera. So let's flow with it.

Of course, there's the issue of what the heck I call these chords. O'kay, I'm going to cheat. I'm going to call the first one a Cmaj7(9)(11), and (wink wink) hey there's no 3rd or 5th in the voicing, sorry about that.

  Cmaj7(9)(11):

   ---  1  ---   F (11th)  (1st finger)
   ---  3  ---   D (9th)   (3rd finger)
   ---  4  ---   B (maj7)  (4th finger)
   ---  x  ---                         
   ---  3  ---   C (root)  (2nd finger)
   ---  x  ---

One more:

  Dm7(9)(11):

   ---  3  ---   G (11th)  (1st finger)
   ---  5  ---   E (9th)   (4th finger)
   ---  5  ---   C (7th)   (3rd finger)
   ---  x  ---                         
   ---  5  ---   D (root)  (2nd finger)
   ---  x  ---

These will test your understanding of our chord construction concept as you work out the rest of the chords in the key of C major, because almost every shape is different here. Here are the chord spellings that indicate why:

   Cmaj7(9)(11)
   Dm7(9)(11)  (or just Dmi11)
   Em7(b9)(11)
   Fmaj7(9)(#11)
   G7(9)(11)    (or just G11)
   Am7(9)(11)  (or just Ami11)
   Bdim7(b9)(11)

So the ii chord and the vi chord have the same shape/spelling, and the iii and vii chords also (since there is no fifth in these chords). Only the 7th and 13th are left to handle. For the 7th on top, we'll "cheat" and go to a 5 string voicing. Why? Because the fingering, using a barre, is much easier. If you're plucking, you can still pluck just 4 strings (5-3-2-1 recommended). The string set we will use is 5-4-3-2-1. The formula is root-5th-7th-3rd-7th. The shapes are the same as the shapes for the 3rd on top voicings, except we are adding the 7th on the 1st string, using the 4th finger.

  Cmaj7:

   ---  7  ---   B (maj7)  (4th finger)
   ---  5  ---   E (3rd)   (3rd finger)
   ---  5  ---   C (root)  (3rd finger)
   ---  5  ---   G (3rd)   (3rd finger)
   ---  3  ---   C (root)  (1st finger)
   ---  x  ---

You can work out the rest; there's only two other voicings. For the 13th, we'll use a root-7th-3rd-13th voicing using strings 5-3-2-1.

Cmaj7(13):

   ---  5  ---   A (13th)  (4th finger or 3rd finger)
   ---  5  ---   E (3rd)   (3rd finger)
   ---  4  ---   B (maj7)  (2nd finger)
   ---  x  ---  
   ---  3  ---   C (root)  (1st finger)
   ---  x  ---

Since the 13th (6th) changes it's position in different minor chords (if you are strictly staying in the key, which we are), the shape is different for a Dmin7(13) and a Emin7(b13). You get to work out the remaining 13th chords.

So there you've got 'em. Simple suggestion: try playing a chord progression of IV-iii-ii-I, using the SAME voicing for each pass over the progression, but CHANGING voicing each time you go back to the IV chord (i.e., first time use root on top; 2nd time use 3rd on top, etcetera; after you can "cycle", jump around randomly).
Record this vamp for 5 minutes, and boogie over it!

Of course, these chords are of big time use when composing and you
need a particular chord over a particular note.You could get into other inversions instead of just the root in the bass...just think, that multiplies the number of chords we just talked about by 7.

Enjoy!