diff --git a/music.md b/music.md
index 2ee8038..adff115 100644
--- a/music.md
+++ b/music.md
@@ -4,4 +4,14 @@
 * [music.resume](music.resume)
 * [music.stop](music.stop)
 * [music.pos](music.pos)
+* [music.duration](music.duration)
+* [music.state](music.state)
 * [music.enabled](music.enabled)
+
+## Constants
+
+* music.INVALID = 0
+* music.PLAYING = 1
+* music.PAUSED = 2
+* music.STOPPED = 3
+* music.DISABLED = 4