SINGING A LULLABY: Christina Aguilera

Serenading her son and how       Christina Aguilera might be rocking the world with her music, but when it comes to 'rocking the cradle,' the Not Myself Tonight singer has to choose a different tune.          She loves spending time with her two-year-old son Max and hunband Jordan Bratman after a long day. She reveals that though she is a pop star and it's only natural that she sings Max to sleep, she has to do it with tracks from the musical movie Mary Poppins.          She says, "I sing my son to sleep with Mary Popins' songs and do really silly things that I won't even mention." Christina is keen to have more children, but at present she is slowly focused on her career and her new album Bionic.