pentatonics again

So here's a way of using pentatonic scales which comes at the issue from the other way around from what we were doing before. Let's start with an F major triad, and let's use minor pentatonics.

Now, the first thing we should stipulate is that you can play whatever you want whenever you want. That's the first rule, and this is basically the opening sentence of Persichetti's Twentieth-Century Harmony. Your ear and musical soul will guide you. On the other hand often what we're doing when we improvise is restating the underlying harmony, and if this is the case then we have to be a little more analytical or "rule bound" in our approach.

Back to the F major triad. Let's see what happens when we start a pentatonic scale on all of its tones: f, a, c.

Right away we can see that the F minor pentatonic (f, ab, bb, c, eb) isn't the best choice if we're aiming at re-stating or -enforcing the harmony. The minor 3rd is what undoes this most. BUT in context the triad might be standing in for a dominant chord, so the minor 7th might work well. And if it is standing for a dominant-type chord it might be a 7#9 chord, in which case the minor 3rd really would sound as the #9 and it would reinforce the harmony. The tones relate to the chord as follows:
f = 1
ab = b3
bb = 4
c = 5
eb = b7

A minor penatonic (a, c, d, e, g) works well as the collection of tones is found in both F ionian and F lydian. It of course won't work if the major triad is actually a dominant chord. The tones relate to the chord as follows:
a = 3
c = 5
d = 6
e = 7
g = 2

C minor pentatonic (c, eb, f, g, bb) could well work, depending on context. If the triad is a dominant-type chord then you get the following:
c = 5
eb = b7
f = 1
g = 2
bb = 4