In reply to Cough Cough.

Christina Aguilera and Mariah Carey are no alto.Aguilra has consistently shown bad technique even on notes that aren't too demanding for any female voice. Mariah Carey has had nodules since childhood, she developed a solid technique years later training with her mother, an opera singer. And she showed countless time to produce great amount of resonance in her upper belts. Overworking, lack of rest are the reasons why Mariah Carey's voice declined. But even today her technique runs circles around christina's.