defined some structural concepts

src/components/PitchLogic.js

@@ -0,0 +1,113 @@
+export const letterNames = {
+    0: 'B',
+    1: 'C',
+    2: 'C-sharp',
+    3: 'D',
+    4: 'D-sharp',
+    5: 'E',
+    6: 'F',
+    7: 'F-sharp',
+    8: 'G',
+    9: 'G-sharp',
+    10: 'A',
+    11: 'A-sharp',
+}
+
+
+export class Pitch {
+    // constructor expects to receive an integer representing a pitch
+    constructor(note) {
+        this.note = note;
+        this.duration = 1;
+    }
+
+    getNote() {
+        return this.note;
+    }
+
+    getDuration() {
+        return this.duration;
+    }
+
+    upOctave() {
+        this.note += 12;
+    }
+
+    downOctave() {
+        this.note -= 12;
+    }
+
+    transposeByAmount(amount) {
+        // a positive int will transpose up, negative int will transpose down
+        this.note += amount;
+    }
+}
+
+
+
+export class Cantus {
+    constructor(...notes) {
+        this.melody = notes;
+    }
+
+    getMelody() {
+        return this.melody;
+    }
+
+    returnLetters() {
+        let output = [];
+        for (let pitch of this.melody[0]) {
+            let reduced = pitch.getNote() % 12;
+            output.push(`${letterNames[reduced]} `);
+        }
+        return output;
+    }
+}
+
+
+
+export class Sonority {
+    // constructor receives an array of Pitch class objects
+    constructor([...notes]) {
+        this.sonority = [...notes];
+        this.numVoices = null;
+        this.consonance = null;
+        this.harmonicPull = null;
+    }
+
+    getSonority() {
+        return this.sonority;
+    }
+
+    setConsonance() {
+        this.consonance = 1;
+    }
+}
+
+
+
+export class Sequence {
+    constructor(...cantii) {
+        this.sequence = [...cantii];
+    }
+
+    getSequence() {
+        return this.sequence;
+    }
+}
+
+
+
+export const cantusFirmus = new Cantus([
+    new Pitch(3),   // D
+    new Pitch(6),   // F
+    new Pitch(5),   // E
+    new Pitch(3),   // D
+    new Pitch(8),   // G
+    new Pitch(6),   // F
+    new Pitch(10),  // A
+    new Pitch(8),   // G
+    new Pitch(6),   // F
+    new Pitch(5),   // E
+    new Pitch(3)    // D
+]);