Watch the Alternate Bass Lines Pt. 1 online guitar lesson by Brad Carlton from Guitar Lab: The Imaj7 IVm6 Progression
Many times a progression is disguised by the bassline so it sounds like something different even though you're coming from the same scales.
In this example, you're simply pedalling the I in the bass for both chords. It creates a slightly different sound when you play the Ebm6/Bb, but nothing changes in terms of your scale or approach.