Oh gosh. Their favorite songs? Well not a comprehensive list because I have ten million OCs... But let's do a few at least. (We'll count joint-ocs for this, too.)
Edwina:
My Chemical Romance - Helena (Sing/Listen)
Scott Joplin - The Entertainer (Play)
Cass:
Taylor Dayne - Tell It To My Heart (Sing)
Cascada - Everytime We Touch (Listen)
Anne:
Death Cab For Cutie - I Will Follow You Into The Dark (Sing/Listen)
Claude Debussy - Claire de Lune (Play)
Yukiko:
Dreams Come True - Hatsuyuki ~Ending Theme~ [First Snow of the Season] (Sing/Listen)
Josephine:
Phoenix - 1901 (Listen)
Clara:
Gigi D'agostino - The Riddle (Listen)