Let's take this comping idea and apply it to a static groove. I know one problem many people have when playing over a static groove is knowing how to create interesting chordal ideas which don't just rely on your stock chord shapes.
In the case of this particular groove, the bass player is outlining an A minor feel. This allows us freedom to be more ambiguous and creative with out chord voicings. If we presume that the chord comes from the key of C (we needn't presume this as there are other keys which contain this chord, but for this example let's keep things simple) then we're assuming that our Am is chord VI. Therefore, we can use an Am pentatonic scale to create all our chord voicings. We always use the minor pentatonic built from the 6th degree of whatever key we're in.
Therefore, we can now use our two sus4 shapes and their inversions to comp and solo over this groove. Remember, the sus4 shapes are built from the root and b7th of the pentatonic scale, so here I'll be using Asus4 and Gsus4 to comp with. Bear in mind that this is just one approach and works best when combined with other chordal approaches such as quartal playing and more standard chord shapes.
In the video I combine a few approaches but stick mainly to the sus4 chords to create my harmony.
Have a go with the backing track at the end of the tutorial and see what you can come up with.