When Sue makes her announcement over the P.A., Becky does an intro and outro on a small xylophone. She is stopped by Sue when she hits too many notes; this is reminiscent of the principal's secretary Blanche in Grease (1978), who does the xylophone intros and outros for P.A. announcements, and also gets carried away.
When Rachel and Kurt are waiting for Blaine so Rachel can kiss him, she says, "I may get a new boyfriend who can keep up with me vocally and in the future give me vaguely Eurasian-looking children". Darren Criss, who plays Blaine, is half-Filipino.
In the scene with the glee kids drinking only Finn and Kurt don't drink. In real life Chris Colfer (Kurt) was under 21 and Corey Monthieth (Finn) was in recovery from drug and alcohol abuse and didn't want to drink.
Kurt is one of the two characters not to get drunk. But his character has been drunk before in the season one episode: The Rhodes Not Take, where he threw up Emma. Chris Colfer was the youngest member of the cast and under the drinking age for the first four seasons.