On April 22's episode of American Idol, renowned composer and lyricist Andrew Lloyd Weber stood patiently trying to teach a blank-eyed Jason Castro the song, "Memory" from one of history's most popular musicals, "Cats."

For the first time ever, the Writers Guild of America, East and the Writers Guild of America, West are celebrating the best screenwriters and their timeless works with the release of the 101 Greatest Screenplays list. The finest achievement in film writing? The classic 1942 love story Casablanca. Rounding out the top three are The Godfather and Chinatown.