American_pop_rock_singers	["Spencer_Albee", "Jason_Farol"]
American_female_pop_singers	["Asia_Nitollano", "Pamela_Polland", "Krystal_Meyers", "Frankee", "Devyn_Rose", "Nellie_McKay", "Shannon_Bex"]
American_male_pop_singers	["B.o.B", "Sam_Tsui", "Joey_Powers"]
American_female_pop_singer-songwriters	["Cheri_Dennis", "Kina_Grannis", "Carly_Simon", "Kaci_Battaglia", "Vanessa_Carlton", "Elizaveta_Khripounova"]
