Fret Ruler fablabchemnitz.de.fret_ruler 0 12tet 25.5 1.35 18 false 25.5 7 0.1 0.125 true true false 2.0 false 3,5,7,10,12,12,15 false 0.014 true 9.75 5 true 0.5 0.3 true 12 true diatonic path