At the end of his poem John Shade (the poet in VN's poem Pale Fire, 1962) says that the day (the last day of Shade's life) has passed in a sustained low hum of harmony:
Gently the day has passed in a sustained
Low hum of harmony. The brain is drained
And a brown ament, and the noun I meant
To use but did not, dry on the cement.
Maybe my sensual love for the consonne
D'appui, Echo's fey child, is based upon
A feeling of fantastically planned,