note:-24 -> freq:hz*0.25
note:-23 -> freq:hz*0.264866
note:-22 -> freq:hz*0.280616
note:-21 -> freq:hz*0.297302
note:-20 -> freq:hz*0.31498
note:-19 -> freq:hz*0.33371
note:-18 -> freq:hz*0.353553
note:-17 -> freq:hz*0.374577
note:-16 -> freq:hz*0.39685
note:-15 -> freq:hz*0.420448
note:-14 -> freq:hz*0.445449
note:-13 -> freq:hz*0.471937
note:-12 -> freq:hz*0.5
note:-11 -> freq:hz*0.529732
note:-10 -> freq:hz*0.561231
note:-9 -> freq:hz*0.594604
note:-8 -> freq:hz*0.629961
note:-7 -> freq:hz*0.66742
note:-6 -> freq:hz*0.707107
note:-5 -> freq:hz*0.749154
note:-4 -> freq:hz*0.793701
note:-3 -> freq:hz*0.840896
note:-2 -> freq:hz*0.890899
note:-1 -> freq:hz*0.943874
note:0 -> freq:hz*1
note:1 -> freq:hz*1.059463
note:2 -> freq:hz*1.122462
note:3 -> freq:hz*1.189207
note:4 -> freq:hz*1.259921
note:5 -> freq:hz*1.33484
note:6 -> freq:hz*1.414214
note:7 -> freq:hz*1.498307
note:8 -> freq:hz*1.587401
note:9 -> freq:hz*1.681793
note:10 -> freq:hz*1.781797
note:11 -> freq:hz*1.887749
note:12 -> freq:hz*2
note:13 -> freq:hz*2.118926
note:14 -> freq:hz*2.244924
note:15 -> freq:hz*2.378414
note:16 -> freq:hz*2.519842
note:17 -> freq:hz*2.66968
note:18 -> freq:hz*2.828427
note:19 -> freq:hz*2.996614
note:20 -> freq:hz*3.174802
note:21 -> freq:hz*3.363586
note:22 -> freq:hz*3.563595
note:23 -> freq:hz*3.775497
note:24 -> freq:hz*4