== Question == 

 My apologies for posting the Josh Groban songs under 'cultural references' a few days ago without a source. I wasn't even thinking about that, to be honest, I just thought somebody else might be interested which Groban songs were featured. Sure got deleted quick, but anyway...I found a blog that confirms what I posted here but I'm not sure if that's a reliable source. To me it seems as reliable as somebody's online episode review, but I thought I'd ask here before adding anything to the article. It's not disputable that it was Groban's music in the episode, right? Even though he wasn't a guest voice.