Watch the Superimposing Pentatonics online guitar lesson by TrueFire from Lead Guitar Greatest Hits Vol. 2
Lesson Source: Shane Theriot's Solo Mojo
If we play the minor pentatonic up a whole step over a min7 chord (in this example Bbmin pent over an Ab min7 chord) we get the same tonalities of the Dorian mode, but in a nice bluesy way. The reason this works is that we get (from bottom to top: 2, 4, 5, 6, root, 9, etc.) a very open sounding modal shape—all just from our tried and true minor pentatonic shape.