diff --git a/lib/improv.js b/lib/improv.js
index <HASH>..<HASH> 100644
--- a/lib/improv.js
+++ b/lib/improv.js
@@ -200,7 +200,7 @@ var ImprovChart = function (chart) {
   this.noteList = makeImprovNoteList(chart);
 
   this.midi = function (filename, options) {
-    return midi.output('improv', this, filename, options);
+    return midi.output('improvChart', this, filename, options);
   };
 
   this.toString = function () {
diff --git a/lib/midi.js b/lib/midi.js
index <HASH>..<HASH> 100644
--- a/lib/midi.js
+++ b/lib/midi.js
@@ -188,7 +188,7 @@ var makeChordTrack = function (chords, options) {
 };
 
 // Return MIDI buffer containing an improvisation
-var improv = function (data, options) {
+var improvChart = function (data, options) {
   var header = makeHeaderChunk(1, 3);
   var tempoTrack = makeTempoTrack(options);
   var noteTrack = makeMelodyTrack(data.noteList, options);
@@ -222,7 +222,7 @@ module.exports.output = function (type, data, filename, options) {
   };
   // Map of type string to function
   var types = {
-    improv: improv,
+    improvChart: improvChart,
     chordChart: chordChart
   };
   var buffer;
Changed value from `improv` to `improvChart` in midi settings to be consistent.