How do you do this in singing?

Question

like what she does at the intro ?

http://www.youtube.com/watch?v=T_YqIaSmfus&feature=related

http://www.youtube.com/watch?v=69Grnh7Qin8&feature=user

^^^ and what she does at the beginning of the song?

how do you develope this skill?

Answer 1

you just move your voice close to the notes you are supposed to sing and drag your voice around that point

Answer 2

The little trilly up and down bits they do are called 'vibrato' which is a repeated fluctuation of pitch. Not everyone can do it but there's no harm in trying. One way of learning is to sing the line in slow motion so that you can get every syllable before speeding it up to make it sound like those trilly bits.

Answer 3

http://www.youtube.com/watch?v=Ey8lZgnUf...