Swapping play builtin melody with begin melody in reference docs

docs/reference/music/begin-melody.md

@@ -0,0 +1,29 @@
+# Begin Melody
+
+Begin playing a musical melody through pin ``P0`` of the @boardname@.
+
+## Simulator
+
+This function only works on the @boardname@ and in some browsers.
+
+```sig
+music.beginMelody(music.builtInMelody(Melodies.Entertainer), MelodyOptions.Once)
+```
+
+### Parameters
+
+* ``melody`` is the array representation of a melody you wish to play
+
+## Example
+
+This example plays the ``Entertainer`` built-in melody.
+
+```blocks
+music.beginMelody(music.builtInMelody(Melodies.Entertainer), MelodyOptions.Once)
+```
+
+### See also
+
+[play tone](/reference/music/play-tone), [rest](/reference/music/rest), [ring tone](/reference/music/ring-tone) , [tempo](/reference/music/tempo), [set tempo](/reference/music/set-tempo), 
+[change tempo by](/reference/music/change-tempo-by)
+