The film was shot in the 2-perf Techniscope format to provide a grainy image reminiscent of older horror films and to save money on film stock and processing. Despite this, "Filmed in Panavision" is listed in the end credits.
Both Jennifer Lawrence and Nolan Gerard Funk have appeared in the X-Men film series: Lawrence in X-Men: First Class and X-Men: Days of Future Past as Mystique and Funk in X2: X-Men United as Captured X-Kid.
Jennifer Lawrence does not actually sing in the movie - she's lip-syncing to session musician Sarah Rayne's voice. However, she did record her own version of one the songs, "All You've Gotta Do is Love", which was described as "not half-bad."