Sterling Knight only sang Starstruck. The rest of the songs were sang by Drew Ryan Scott, because Knight was cast late in the process and did not have time to learn all the songs.
Danielle Campbell was only 15 when the movie aired.
Both Sterling Knight (Christopher Wilde) and Brandon Mychal Smith (Stubby) starred in Disney Channel's Sonny with a Chance (2009).
During the party scene at Christopher Wilde's house just after he first meets Jessica, "Welcome to Hollywood" by Mitchell Musso {previously Oliver on Disney's show Hannah Montana} which was released the year previously is heard playing in the background.
In the party scene where Christopher (Sterling Knight) brings Jessica (Danielle Campbell) to his house and he is singing the song "Hero," there is a shot where you can see her elbow in the corner of the screen. The actress had the flu, so that's her stand-in.