Update and rename noteToFreq,js to noteToFreq.js

noteToFreq.js

@@ -0,0 +1,48 @@
+function parseNote(note){
+  if(["#", "b", "♯", "♭"].includes(note[1])){
+    return {   letter: note.slice(0,2), octave: parseInt(note.slice(2))||null   };
+  }else{
+    return {   letter: note[0], octave: parseInt(note.slice(1))||null   };
+  } 
+}
+
+noteMap = [];
+octave = -2;
+notesSharp = "C C# D D# E F F# G G# A A# B".split(" ");
+notesFlat = "C Db D Eb E F Gb G Ab A Bb B".split(" ");
+notes = "CC CD DD DE EE FF FG GG GA AA AB BB".split(" ");
+function normalizeLetter(letter){;
+  switch(letter[1]){
+    case "#":
+    case "♯":
+      return notes[notesSharp.indexOf(letter)];
+      break;
+    case "b":
+    case "♭":
+      return notes[notesFlat.indexOf(letter)];
+      break;
+    default: //undefined
+      return letter.repeat(2);
+      break;
+  }
+}
+while(octave++ < 9) noteMap.push(...(notes.map(letter=>(letter+octave))));
+
+function noteToMidi(note){
+  const {letter,octave} = parseNote(note);
+  return noteMap.indexOf(normalizeLetter(letter)+octave);
+}
+
+
+
+
+
+
+
+function ntf(note, tune = "A4=440"){
+  tune = tune.split("=");
+  tune = {note: noteToMidi(tune[0], pitch: parseInt(tune[1])};
+  note = noteToMidi(note);
+  interval = note - tune.note;
+  return interval
+}