What is the significance of the yellow note in Chestnut Tree Cafe?
"There came into it—but it was something hard to describe.
It was a peculiar, cracked, braying, jeering note: in
his mind Winston called it a yellow note."
Part 1 Chapter 7.
Something changed in the music that trickled from the
telescreen. A cracked and jeering note, a yellow note, came
Part 3 Chapter 6.
Why is the yellow significant? It has appeared towards the beginning and the end of the book.
My interpretation of the yellow note is that it has come to signify the cowardice and betrayal that have now combined to destroy Winston. He and Julia both discuss the fact that they betrayed each other, that under the incredible torture they both gave up the other, that in the end "All you care about is yourself." Because of this, the affection he felt for her, the only really true thing in his life, has now become as cracked and yellow and empty as everything else around him.
The "jeering" note serves to remind him of this, to remind him of his deepest inner cowardice, that which betrayed all the hatred he felt for the party, all the bravery he thought he possessed that allowed him to consider such things as helping the proles to revolt, etc. The music is not just despicable or empty and tinny now, it is yellow and it jeers at him, mocking him as a human being.