As we begin substituting extended chords in the place of traids and power chords to spice up our old progression, we often ask whwether or not there are rules or generalizations for when playing these different chords...One of the most important things to consider when choosing a substitute voicing is the quality of the chord to be replaced. You'll wan't to catagorize the chord as being major (containing a major 3rd) minor (containing a minor third), or dominant (major third with b7)in tonality. This is important because chords can be swapped easily, without fear of clashing with the existing melody. The only limitation is how far you want to go with the complexity of your voicings. Let the stryle of the music you're playing be your overall guide.

-Joseph