There is a lot of Van morrison songs that are composed of maj. 1 4 5 progressions...yet when a parrallel blues / minor penta is used to solo with it sounds very wrong. Same holds true w/country music and songs of that flavor.

Using the parrallel minor works, and can be very cool, but there has to be certian factors in place for it to work well, it's not a garauntee.