Help finding an episode

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Hello there, I'm currently trying to find an episode of Sesame Street, in which Whoopie Goldberg makes a guest appearance. I don't remember the exact details of the episode, but I know that it was shot in the 90's and that Whoopie Goldberg was playing some sort of magician with a large purple robe. Somewhere in the episode (I believe at the end), she makes a string quartet appear (which I am in). So if anyone could provide any information to the title of that episode, or to where I could obtain a copy, I would be much obliged. Thanks.