Transcript:
Schroeder stands next to Charlie Brown on the field as the latter whistles at Patty as she walks by down the lane.
Charlie Brown grimaces as Patty continues walking by and snorts in disgust.
He watches as Schroeder whistles an entire musical piece at Violet as she walks by.
He grimaces darkly as Violet and Schroeder walk down the lane together, smiling at each other.
Original comic:

Anyone recognize what piece Schroeder is whistling?
Very impressive that he can whistle two notes at once anyway
I would say Träumerei by Schumann.
Edit: Confirmed
I played it out to see if I could tell, but I don’t recognize it. Its not a particularly romantic or melodic thing tbh. Kinda mid.
Someone else already confirmed it, but here’s a page with some trivia like that:
https://en.wikibooks.org/wiki/Annotations_of_The_Complete_Peanuts/Print_version
It’s kind of hit-or-miss, but does list this one:
Charlie Brown is delivering the traditional whistle of appreciation for feminine beauty (though it usually has two notes: WEEEET-WOOO), and Patty takes offense. Schroeder, being more musical, delivers a mini-concert to Violet and gets to walk off with her. It is the melody to “Traumerei” from Schumann’s “Scenes from Childhood” for piano.
I’m terrible about reading notational music, but… isn’t that “Happy Birthday to you?”
It’s definitely not Happy Birthday.



