partial chord or chord fragment are both accepted terms. if you're specifically playing 2 notes, it can also be called a double stop.
Thought I'd post a word of caution on these terms - stuff like "partial chord" and "double stop" are really instrument specific, and they don't always mean what you think they do.
David's earlier example starts with a "full" C chord, x32010, but it also has three other "full" C chords (xxx010, x320xx, x3201x). All of these have the notes C, E, and G, and that's all you need for a "full" chord. A "partial" (or "implied") chord is when you play a voicing that doesn't include all the notes it's supposed to have - when David shows xxxx10, xxx01x, and xx20xx, these imply a C chord, because they're each missing something.
Context has a lot to do with it. If you play xx23xx, you can imply a C7 chord... but if you play a "full" C7 as x32310, you're not actually playing a "full" C7 - there's no G note! When a chord is supposed to have four (or more) notes, the fifth is actually optional; this means x32310 is still a "real" C7 chord - but to play a "full" C7, you'd need to finger it 3x231x or xx2313.
When you play two notes, guitarists and violinists call them double stops - other instrumentalists would call them "intervals". Music theory geeks will also call them "dyads", but usually only when talking amongst themselves :)
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Thanks for the clarification on that, Tom. Makes good sense.
And a quick question - I'd always thought that "double stops" inferred playing two adjacent strings. Is that part of the accepted terminology?
Peace
Yep, double stops are done on adjacent strings. The term started with violin - because the bridge is so curved, the most they can get is two strings under the bow at once, and the strings have to be next to each other. Most books I have (guitar and other, like Piston's Orchestration) say the adjacent strings are needed for it to be a double stop.
But I've seen the term applied to a other instruments, like marimbas - there they mean playing two notes with the mallets held in one hand. So it really depends on the crowd you're hanging around... most instruments don't use the term at all, and the ones that do can mean different things by it.
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I've always thought of double stops as being on adjacent strings on a violin, viola etc. - but now I'm thinking about it, it seems overly strict. When the music calls for pizzicato, a violinist can play two non adjacent strings at the same time by plucking with fingers instead of bowing. I wonder if those are considered double stops too in the violin world.
Unlike most other guitarists I meet, I've also always thought of double stops as a technique rather than a sound , i.e., a way of producing an interval, rather than the interval itself. The "stop" part of the name comes from "stopping" two strings by pressing them down onto the fingerboard, although I don't know if violinists (like guitarists) allow open strings under their definition of double stop.
I only use the term in relation to violins etc., because on guitar, playing two notes at the same time is so simple it doesn't need a special name. And if I'm talking about the actual sound, I always call them intervals, never double stops, and most definitely never dyads :D
