hello,
I've read some old threads on here looking for information about sus chords and am more confused than I was when I started...
in basic, useful for bassists terms, is a sus chord a chord with the 4th instead of the 3rd? in that case, should you avoid playing the 3rd in a line under sus chords? (before I get attacked, I know I can play what I like and should use my ears, but a bit of understanding would leave my ears better informed...)

Generally, the sus is a device to create harmonic tension and it's not meant to be resolved. And generally, if you play the 3rd, you squander the effect. But you're certainly free to experiment. I can't say never or, for that matter, always about most things in harmony.

A sus chord can function a few different ways, but most simply -- yes, it has a 4th inplace of the 3rd.


Here're a few tips.

In a traditional harmonic place, where the sus chord resolves to a major chord a 4th up (G7sus to C), the G7sus can be approached like a D-7, a G7, or even a F triad over G (F/G). You can boil this down simply to the Ionian (root position major scale) of the parent key -- in this case, C. So, D dorian and G mixo-lydian are pretty useful.

If the situation is similar to the above, but the resolution is minor, then you can apply the same sort of approach, but take care that you are dealing in minor. Listen to the chordal instrument and melody to get a proper sense of how the chord is being used. So, for a G7sus (b9), you can approach the chord like a D-7(b5) or a G7 alt. Your base scale would be C minor (C aolian, based on Eb Ionian). You can approach this with D locrian, G phrygian (both just a Eb major scale, really), or even go further and get into some melodic minor and diminished things (which can also be used successfull above).

If the sus chord is static, frequently used in fusion and 60's modal kind of stuff, you can treat the sus chord as you would a regular ol' dominant 7th chord -- pentatonics and the like.

cheers ray, lots of useful stuff to play with

Cool :)

Funny... when my old eyeballs first passed across this thread, I misread it as "Sus4 for drummers"...

That is a topic unto itself, and probably belongs in Jokes.