diff --git a/app/scripts/services/bar_generator.js b/app/scripts/services/bar_generator.js
index 6cbb288..5be9d9e 100644
--- a/app/scripts/services/bar_generator.js
+++ b/app/scripts/services/bar_generator.js
@@ -2,6 +2,7 @@ import _ from "lodash";
 
 import KeyConverter from "../services/key_converter.js";
 import LevelService from "../services/level_service.js";
+import Vex from "vexflow";
 
 const baseNotes = "cdefgab".split("");