These slide rules simply show every note on the neck for any key you choose with easy hand positions. This is where you put your fingers for any key. Easy to use. Pick a key, set the slide, and play from the hand positions. To improvise, play 2 or 3 notes at same time, or play fast and slow phrases using mainly the notes that are showing, and be sure to repeat phrases. You provide the improvision, or recombining of notes to phrases, and phrases into leads. It is quick mastery!