 The episode was written by Tim Long and directed by Mark Kirkland . Upon airing , it was met with mixed reception from television . " Elementary School Musical " was viewed by 7 @.@ 8 million viewers and attained a 3 @.@ 7 / 8 rating in the 18 – 49 demographic , according to Nielsen ratings . The episode features guest appearances from Lea Michele , Amber Riley , Cory Monteith , Jemaine Clement , Bret McKenzie , Ira Glass , and Stephen Hawking , as well as several recurring voice actors and actresses for the series . 
