Watch the Strategy 1: Consider Character online guitar lesson by Jon Herington from Ear IQ: Soloing Strategies
Let's take a look at "H Gang". As with a lot of Donald's writing, you can be lulled into a false sense of security as a soloist by the way a section will start very simply. But almost always there's a sharp harmonic curve up ahead - and though it's a really short solo section, this tune is no exception. So, we have 2 bars of Dmi9, 2 bars of Ami7, 2 more bars of Dmi9 - pretty simple so far - all one key, and pretty easy to negotiate. Then in the 7th bar, we get a C9 chord - so we get the Bb now instead of the B natural in the original key - and then we get a split bar of Fmi6 and Ebdim7, which get your ears working. The solo section ends on the next bar of F6/9 which begins a vamp that existed before, and we're all done.