Currently I'm playing in a quartet and one of the pieces we are doing is Sister Sadie.
At several times my music leaves me with a G7 for several bars with the instruction to comp - but I find it difficult to comp on a single chord for long periods of time, for example 8 bars.
How do pianists such as Horace Silver keep a single chord interesting for so long, and how can I do the same?
Listening to that recording what you hear is Horace playing either rhythmic figures constantly or using rhythm to convey information instead of using harmonic invention. This is really hallmark of this specific kind of style - compare with Lee Morgan's Sidewinder or Herbie's (original) Watermelon Man. The Horace recording recording itself features a classic kind of shout chorus, too. To me this is a dead giveaway that the most important ingredient of this tune is the rhythm as opposed to the harmony. So the gist of successfully comping on a tune like this would be to find rhythmic figures that are compelling to play and latch onto rather than harmonic figures. "Dance with the hands like Horace" might be a short way of putting it. But this is all assuming you're trying to play it in a way that reflects the recording - i.e., you're not trying to to a reharm or Snarky-Puppy-ify it.
At the very least, assuming it's in key C, I'd be using Dm7 as well as the G7, and probably G9, G11 and G13 too. And even G7+ towards the end of the vamp period.
A moving bass line is possible. This can make a nice counter melody to the melody. A scale wise up or down bass doesn't really affect the harmony.
When you're comping, you are comp -limenting the music. You do this by focusing on the following elements:
The golden rule of all group improvisation ever is "Yes, and...". Hear what the other musicians are playing and think what would sound good there from your instrument based on the above elements (and anything else you can think of).
It's really no different than regular comping, except that when you're on one chord for a while you need to place more importance on the other elements (rhythm and upper structure harmony for example). Just remember to listen before you play.
