#1
Or do they mostly just get thrown together to sound cool. Is there any rule to power chord riffs or songs?
#2
well, it depends on which power chords you are playing
Main Rigs
Guitars
Thineline tele with SD lil '59

Ibanez Artcore AM-73

Line 6 Variax 500


Effects

Line 6 X3 live
Digitech RP-500
Ibanez Weeping Demon


Amps
Roland JC-120
Rocktron VT-60
#3
A power chord is a root and a fifth. The root is the actually chord you play I.E. an E power chord has an E root. The easiest way to find the fifth, without getting into theory, is to find the note 7 frets higher. In the case of E it is B.

Edit:
Also, I wanted to point out that the reason why power chords work so well together is because they don't have a third.

Without the third you don't lock your self so strongly into a key.
Main Rigs
Guitars
Thineline tele with SD lil '59

Ibanez Artcore AM-73

Line 6 Variax 500


Effects

Line 6 X3 live
Digitech RP-500
Ibanez Weeping Demon


Amps
Roland JC-120
Rocktron VT-60
Last edited by teknotard at Mar 7, 2008,
#4
They are indeed in a key. Take the key of E minor (E,F#,G,A,B,C,D) for instance. Say you were to play an F# power chord. The notes would be F# and C#. C# is not in E minor, so you'd have to play F# and C (which is a tritone) in order to stay within it.

By the way, they aren't actually "chords." They only consist of two notes, which is an interval. A chord has three or more different notes.
Last edited by AbstractDeth7X at Mar 7, 2008,