This song is in the key of G minor; the notes that repeat throughout are G and Bb, respectively.
Brooke's original costume in Break a Leg was from ALDC student, Stephanie Pittman, who used the costume for her "Letter by Letter" solo in 2008. The costume was soon used again for Brooke's unseen trio with Chloe and Maddie in New Girl In Town.
The ALDC has reused the concept of "The Diary of Anne Frank", with the first being Stephanie Pittman, who performed the solo with the same name back in 2009.