diff --git a/.gitignore b/.gitignore
index 08f01db..273e392 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
 /node_modules
-.gitignore
\ No newline at end of file
+/built
\ No newline at end of file
diff --git a/app.js b/app.ts
similarity index 98%
rename from app.js
rename to app.ts
index cefddb8..c5cc0b2 100644
--- a/app.js
+++ b/app.ts
@@ -1,3 +1,4 @@
+import * as Tone from 'tone';
 import {
     sopranoTones, altoTones, tenorTones, bassTones,
     extractPitchset, 
diff --git a/built/app.js b/built/app.js
index d03acf3..d3bf093 100644
--- a/built/app.js
+++ b/built/app.js
@@ -1,3 +1,4 @@
+import * as Tone from 'tone';
 import { sopranoTones, altoTones, tenorTones, bassTones, extractPitchset, } from "./src/toneGeneration.js";
 const pitchsets = [sopranoTones, altoTones, tenorTones, bassTones];
 // initialize four synth voices
diff --git a/built/src/styleUtils.js b/built/src/styleUtils.js
index 06f598b..5f8712b 100644
--- a/built/src/styleUtils.js
+++ b/built/src/styleUtils.js
@@ -7,6 +7,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };
+import * as Tone from 'tone';
 export const startButton = document.getElementById("start-tone");
 export const synthButton = document.getElementById("synth-button");
 export const showStart = document.getElementsByClassName('show-on-start');
diff --git a/built/src/toneGeneration.js b/built/src/toneGeneration.js
index fbc809e..7c408fb 100644
--- a/built/src/toneGeneration.js
+++ b/built/src/toneGeneration.js
@@ -9,7 +9,7 @@ export const bassTones = ["C2", "D2", "E2", "F2", "G2", "A2", "Bb2", "B2", "C3",
 const musicalPitches = ['A', "Bb", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"];
 export const extractPitchset = (pitches) => {
     // 1) determine pitch set from given array of pitches
-    let pitchset = [];
+    let pitchset;
     for (let each of pitches) {
         // filters numbers from above tones
         const str = each;
@@ -20,7 +20,7 @@ export const extractPitchset = (pitches) => {
         pitchset.push(pitchNumber);
     }
     // these are sorted from lowest to highest index (something like an interval vector)
-    pitchset.sort((a, b) => a < b);
+    pitchset.sort((a, b) => a - b);
     console.log(pitchset);
     return pitchset;
 };
diff --git a/src/styleUtils.js b/src/styleUtils.ts
similarity index 89%
rename from src/styleUtils.js
rename to src/styleUtils.ts
index 3b7a4a0..8231e4c 100644
--- a/src/styleUtils.js
+++ b/src/styleUtils.ts
@@ -1,11 +1,13 @@
+import * as Tone from 'tone';
+
 export const startButton = document.getElementById("start-tone");
 export const synthButton = document.getElementById("synth-button");
 
-export const showStart = document.getElementsByClassName('show-on-start');
-export const hideStart = document.getElementsByClassName('hide-on-start');
+export const showStart = document.getElementsByClassName('show-on-start') as HTMLCollectionOf<HTMLElement>;
+export const hideStart = document.getElementsByClassName('hide-on-start') as HTMLCollectionOf<HTMLElement>;
 
 export const showMore = document.getElementById('info-button');
-export const moreInfo = document.getElementsByClassName('more-info');
+export const moreInfo = document.getElementsByClassName('more-info') as HTMLCollectionOf<HTMLElement>;
 
 export let appReady = false;
 
diff --git a/src/toneGeneration.js b/src/toneGeneration.ts
similarity index 92%
rename from src/toneGeneration.js
rename to src/toneGeneration.ts
index 9787eaf..59224b6 100644
--- a/src/toneGeneration.js
+++ b/src/toneGeneration.ts
@@ -9,9 +9,9 @@ export const bassTones = ["C2", "D2", "E2", "F2", "G2", "A2", "Bb2", "B2", "C3",
 // this is focused on base-12, something computers understand quite well
 const musicalPitches = ['A', "Bb", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"];
 
-export const extractPitchset = (pitches) => {
+export const extractPitchset = (pitches: string[]) => {
     // 1) determine pitch set from given array of pitches
-    let pitchset = [];
+    let pitchset: number[];
 
     for (let each of pitches) {
         // filters numbers from above tones
@@ -25,7 +25,7 @@ export const extractPitchset = (pitches) => {
     }
 
     // these are sorted from lowest to highest index (something like an interval vector)
-    pitchset.sort((a,b) => a < b);
+    pitchset.sort((a,b) => a - b);
     console.log(pitchset);
 
     return pitchset;
diff --git a/tsconfig.json b/tsconfig.json
index e583438..5fd7e6a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,7 +2,8 @@
     "compilerOptions": {
       "outDir": "./built",
       "allowJs": true,
-      "target": "es2016"
+      "target": "es2016",
+      "moduleResolution": "node"
     },
     "include": ["./src/**/*"]
 }
\ No newline at end of file