Hey Reggie, I have a harmonica rack on a washboard too. I couldn't use a conventional rack, (I became un-coordinated on both instruments) so my wife built one to custom fit on top of the washboard, and it works great! My advice to you guys out there, if you meet a woman that can build things to accomodate your harmonica, marry that girl. I did. BTW, overblow refers to the technique of bending the blow notes as well as the draw. It's way beyond me.