In S1E15, Emily says to Christopher and Lorelai, “Do you remember when you two were, what, 10? And you put on that adorable show for us?” Lorelai asks, “What show, Mom?” Christopher answers, “Lucy, Schroeder, you laying on the coffee table…” Lorelai finishes, “You pretending it was a piano!” Richard asks Christopher if he wrote the song they performed- “Suppertime.” Lorelai says, “Dad! That’s from ‘You’re a Good Man, Charlie Brown.’ It’s a famous musical!”
Schroeder is a piano-playing friend of Charlie Brown from the “Peanuts” comics. Lucy has a crush on him. Lucy laying on the piano while Schroeder plays is a classic scene from the comics.
“You’re a Good Man, Charlie Brown” is a 1967 musical written by Clark Gesner. It was also adapted into TV Specials in 1973 and 1985. “Suppertime” is a song in which Snoopy dances and rejoices that Charlie has finally brought him supper.