Perfect example; the Blues pentatonic scale. The old guys flatted the third and seventh to get an approximation of African scales. But I am not sure perfect pitch is dependant on a particular ethnic musical scale. I think it is something different. If you decide to make all your music in the mixolidean mode that shouldn't mean someone with perfect pitch no longer could distinquish notes. Then again I don't have perfect pitch so I really can't say. Ask a good piano tuner.