I like the topic dirt, despite the lack of posts, there is much room for discussion of this topic. Well, from a classical sense, the piano is far superior in chord structures. For a long span of time certain aspects of music were unthinkable, and in ancient Greece, almost unethical. During the time of Bach and other composers, parallel octaves and parallel 5ths (a movement from one chord to another chord in which the octave or the 5th were in the same voice that they were in the previous chord) would sound to them like a series of half steps would sound to us. Many things that are acceptable in modern music were cacophonous to them. And it goes without saying that music is much different now than it was then. And chord knowledge is pivotal to any versatile guitarist. But noticingthemistake makes an excellent point on omitting certain voices from the chord structure. Understanding the way that the chord blends with each tone, then choosing to add or omit notes that give the desired sound is a great tool to have.

To digress from my rant. I aree with you mistake, Metallica's direction has been disappointing. But Hetfield is a great rythm player in terms of strumming 16ths and triplets for a 7 minute metal song. That's more rhythmic endurance than I have. Metallica isn't much for unique chords, but the music is great. Jon Frusciante of the Red Hot Chili Peppers is probably my idol of rhythm guitar. He plays amazing parts, and I have never been more impressed with any rock guitarist ever in terms of chord utilization. You could find some jazz players who would probably swallow him whole, but to play rock with his style is simply astounding.