In Nothing But the Truth by Avi, the first time Philip hums in class is his first day with Miss Narwin as his new homeroom teacher. He has just told his friend, Ken Barchet, that he is going to find a way to get out of both Miss Narwin's English class and her homeroom.
As always, at the end of the morning announcements, the speaker says,
"Please all rise and stand at respectful, silent attention for the playing of our national anthem" (Avi 34).
Philip ignores the rule and begins to hum loudly enough for Miss Narwin to hear him. She asks Philip if he's the one making noise, and he replies, "Just humming (Avi 34). Miss Narwin asks him to please stop, but he continues, saying, "Mr. Lunser doesn't mind" (Avi 34). This is a reference to when Phil was in Mr. Lunser's homeroom, and Mr. Lunser threatens in a good natured manner to have Phil sing the anthem as a solo.
Philip continues to hum and tries to argue with Miss Narwin until she finally says, "Now! Thank you" (Avi 35).
At that point the anthem is over, and Philip stops.