Is a power chord a chord??

It's just called a chord as a matter of convention but, as Netzok says, it's not a chord. In fact, "power chords" figure prominently in rock and blues because lacking a third, they are neither major nor minor chords but blend with both. They also often therefore sound more clean on an electric when distortion is used.

A power chord is not a chord, it's an interval because it contains two notes: the root and the perfect 5th, I've heard the word diad also used. A triad is a three note chord, so I would call a chord anything with three different notes or more (a three string power chord doesn't count because a different interval will still have the same note name), it doesn't have to have a third necessarily, a suspended 2nd or 4th only has a root, 2nd/4th and a 5th.

The term "chord" isn't so strictly defined. Loosely speaking, a chord is any combination of notes that produce a harmonic effect. That means any amount of notes from 2-note intervals (dyads) upwards are chords. But if the notes are the same pitch or one or more octaves apart, the harmonic effect is considered negligeable, to the extent that, even in this loosest of definitions, those aren't considered chords.

More strictly, and in accordance with the kind of harmony that's developed here in the west, chords are considered to have at least three notes, (excluding unisons and octaves). Triads are three note chords that are built from thirds, but if the 5th of the triad is omitted, as happens often in real music, the chord is still considered a triad and legitimate chord - even though it has only two notes. (In context, the missing 5th is implied - it doesn't have to be actually heard.)

It's much the same with a power chord - You can think of it as a two note perfect fifth interval, or as a triad with a missing third. Even though the third of the chord is missing, you can usually tell whether the missing note would be a major or minor third - because it's still there in spirit - so it qualifies as a chord as much as a triad without a fifth does.

Well, I'm not going to argue that because I'll admit I'm not a theory expert, I was just always taught that chords are 3 simultaneous notes or more and an interval is 2.

It depends on who's school of thought you adhere to.

In what I would argue is the majority view of western music theory, a power-chord is counter-point, and a chord requires 3 pitch-classes.

But there are other views which are equally valid and usable.

Context is also important. As FS points out, in many contexts you can view an interval is a chord with a missing note.

Fretsource is correct, you can eliminate a note and still have a chord... IF the context tells your ear it's a chord.

When you look at a "power chord" in context, it can give you a chord progression. The Kinks "You Really Got Me" gives you the context of a I-IV-V progression.

But when you look at a "power chord" by itself, it's not a chord.

From the Harvard Dictionary of Music:

A chord is a simultaneous sounding of three or more tones (two simultaneous tones are considered an interval rather than a chord).

Fretsource is correct, you can eliminate a note and still have a chord... IF the context tells your ear it's a chord.
thats interesting and I believe relates to this question
http://forums.guitarnoise.com/viewtopic.php?t=34164

So if Eadd11 is E G# B A and Eadd11 without the fifth is E G# A
how do we notate this new chord ? Do we still just call it Eadd11

Paul

Fretsource is correct, you can eliminate a note and still have a chord... IF the context tells your ear it's a chord.
thats interesting and I believe relates to this question
http://forums.guitarnoise.com/viewtopic.php?t=34164

So if Eadd11 is E G# B A and Eadd11 without the fifth is E G# A
how do we notate this new chord ? Do we still just call it Eadd11

Paul

Thinking about it since the other day...the A and E would be an A5 powerchord....and the G# would be the 7th - so Amaj7th seems better, with the third implied, as if Amajor is the "default" chord we hear when we play an A5 "chord." Although in context, it could just as easily be an E11 with the fifth implied....and if you're playing an E bass note (I seem to recall that's the case) then E11 would seem to fit. For the benefit of other musicians, you'd probably notate it as either "E11(no5)" or "Amaj7(no3rd.)"

:D :D :D

Vic

Lots of chords are ambiguous. Which it is would depend on the context in which it is used.

I've been under the impression that 3 notes make up a chord, but if somebody were to call a powerchord with 2 notes a chord I certainly wouldn't argue the point.

I think a better way of saying it is absent of all other information you'll need a minimum of three notes to define a chord. However two notes and the surrounding chords, key, context etc. will allow you to infer the chord.

It turns out it is a chord. I had always thought a chord needed three tones, but according to the Grove Dictionary of Music, a fairly standard and authoritative reference work, a chord is defined as the "simultaneous sounding of two or more notes". Here's the definition in full:
Chord
(Fr. accord; Ger. Akkord, Klang; It. accordo).
The simultaneous sounding of two or more notes. Chords are usually described or named by the intervals they comprise, reckoned either between adjacent notes or from the lowest: the Triad, for instance, consists of two 3rds (reckoning between adjacent notes) or, equally, a 3rd and a 5th (reckoning from the lowest note). In functional harmony the Root of a chord is the note on which it seems to be built. If the lowest note of the chord is also its root, it is said to be in root position; if not, it is said to be in inversion (see Inversion. If a triad is inverted it becomes either a Sixth chord or a Six-four chord.

See also Added sixth chord; Altered chord; Augmented sixth chord; Diminished seventh chord; Dominant seventh chord; Doppelleittonklang: Doubling (i); Mystic chord; Neapolitan sixth chord; Ninth chord; Seventh chord; Spacing; Substitute chord; and ‘Tristan' chord.
□

© Oxford University Press 2007
How to cite Grove Music Online

That definition would qualify a power chord as a chord.

Just a little thought that sneaked up on me - it's called a power chord, not a power interval or a power diad - but a power CHORD. Musenfreund's dictionary would seem to bear that out....

Take a loot at the "Steven Stills" tuning for "Suite Judy Blue Eyes"....low to high, Eb Eb Eb Eb Bb Eb - what do you get when you strum all six strings? Sounds like a chord to me....maybe an extreme example, but there are only two notes in there.

:D :D :D

Vic

a power-chord is counter-point

huh? Power chords generally use similar motion...and they are perfect fifths. So what exactly do you mean?