A more modern application would be "Mary Jane's Last Dance." It's recorded in A minor and a G major harp is used, making it Dorian mode.
And your usual cross harp for blues is a 4th up so it's Mixolydian, more or less.
I'm still not awake. After two edits, I hope that I have it right!!
Yeah I have all the harps, and that's my go-to, if it's in a minor key, go down a step. If it's a blues tune, cross harp at the 4th. If country, same key.
I tried to explain that to a guy that only plays harp ("see, ya play a 4th, it's the same position on the next string..." ) that didn't go well.