In the friends episode 12 of season 2, Phoebe chats with a man who hires her to play in concert. And the man replies, "Maybe if you just played some regular kiddie songs... Like some stupid, big, like, purple dinosaur? You don't have to be Barney."
Since I did not understand, I googled what he meant by "Barney". Thanks to Barney Stinson- "How I met your mother", I now will never know what he meant.