I have seen this video SO MANY TIMES. Kelly even back then had a nice chest/head transition. Beyonce, you could tell was a little nervous but getting into it did a great job. On the Kelly vs Beyonce vocal debate, Kelly does have a pure light airy pretty tone, where Bey's tone is fuller(even on the video you can hear it), with a bit more color and dynamics even back then. Lot's of Melismatic Phrasing too(vocal runs). And was/is the better belter too. Bey consistently belts above D over Tenor C and her signature note is the F over Tenor C, Kelly is more Tenor C to E-Flat(That is a note) over Tenor C and uses head voice more. Kelly probably need more work on perfecting her vocal stylings. Someone said that DC was built off Beyonce's strengths, I agree with that. So Kelly would need an overhaul of her stylings to set herself apart. Not to mention work on her confidence. But she can sing. No doubt. DC would have not been DC without those two, even when Toya and Tavia left, they were able to keep going because of those two. So Kelly and Bey fans shouldn't fight over who is better especially when it is a preference thing anyway.