Tina Fey, the star and creator of the series "30 Rock", admits she and her castmates often take creative liberty with the music in order to keep production costs low.
She says, "We started making our own songs because it's just free. We had this scene where it was like (we needed) this really crunchy lady music. And so we wanted to play Joni Mitchell and we couldn't pay for it. So I was like, 'We'll just make it up.'"
But Fey wasn't exactly prepared when it was time to shoot the scene.
She adds, "It's so bad. I forgot to write it so I had to improvise it. If you have to improvise Joni Mitchell you just have to sing really high with a Canadian accent. So I kept naming places in Canada like, 'Oh, Medicine Hat.'"