Mariah Learns Humidifier Trick From Luther
The singer has often been ridiculed for her vocal demands, but she insists she has to take care of her voice.
She explains, "I sleep as much as I can the night before (a show). We have to sleep to hit the notes.
"I need humidifiers when I sleep because it's good for my voice. Luther Vandross, God bless him, told me that."