Excellent article. Tune your Resonator`s to D in order to use a slide. Try wearing your slide on your pinky so that you can play cords behind the slide. Play your slide over the top of your frets, Each fret gives a dfferent note. Try playing to slided frets next to each other around the twelth fret and then drop down to play cords This is the Robert Johnson style of slide play. Frets 3,5,7,9.12 and 15 are excellent areas to use your slide. If you dont have a resonator and would like to try slide on a acoustic guitar tune down to D tuning and have fun. When you get a resonator in your hands you will have already mastered it.