Watch the Modal online guitar lesson by Mimi Fox from Jazz Anatomy
Jazz players love to open things up a bit over modal tunes like So What, Impressions, Footprints and hundreds of others. You can even apply some of the concepts here over minor II-V-I vamps. In order to play hip chords over modal pieces you must learn your chords up and down the length of the guitar. It's great to stay in one area and know all your chords, but it's even better to be able to have the flexibility to play any chord anywhere on the neck. Practice this study until you see and hear it in your sleep!