Notes:

• The common ii-V-I chord progression uses all three "chord families": minor 7, dominant 7 and major 7.

• It's what kind of 3 and 7 a chord has that gives it its essential character. Minor 7 (b3, b7), Dominint 7 (3, b7), Major 7 (3, 7)

• All three chord families have a ("perfect") 5th. That chord tone doesn't add much to the chord's color, so can often be dropped.

• Seventh chords have 4 notes; 9th chords, 5 notes; 11th chords, 5 or 6 notes (must drop a major 3rd). Thirteenth chords also have 6 notes, because you don't play the 11th.

• Because the guitar has just 6 strings, and because of the way it's laid out, it's often difficult-to-impossible to play all the (theoretical) notes of a chord. Some, we often have to make decisions about which notes to drop and which to keep.

• 2 and 9 are the same note. Likewise, 4 and 11 are the same, as are 6 and 13.

• 1-4-5-b7 make a "suspended 7th chord" (the 4 takes the place of the 3). If you add a 9th, it becomes a (dominant) 11th chord: 1-(no 3)-5-b7-9-11.

• A "major 11 chord" exists in theory, but is very dissonant (sounds like crap ;-), and never played. It includes 2 very jarring intervals; a b9 and a b5 ("tritone").

• A "minor 13 chord" also exists in theory, but is rarely used, as it's also quite dissonant. However, in some contexts, you may decide you want that sound. So, as in all music, if you like certain sound, by all means use it!

• Mix them up! You don't have to play (for example), minor 9 to dominant 9 to major 9. You can use any minor family chord to any dominant family chord to any major family chord. Example: minor 11 to dominant 7 to major triad.

• See this PDF for other common 9th, 11th and 13th chord "grips."