Yeah, I've got to agree about the harmonies, Federico. Love how it doesn't pull KT off pitch though! Check out the version KT and Daryl did of this on Live at Daryl's House which should be out there on RU-vid, though. It's downright masterful, as is their version of H&O's "Out of Touch".
The melodic and the harmonic combination is arranged in such a way that whenever either one starts to get out of bounds the other one pulls it back in line. Its fantastic composition and a very delicate and subtle one, much suited for a female lead, even though KT herself just gets by during most of her previous live performance but one at Daryll's house recording session is perfect.
The vocal harmonies in the chorus are a little bit out of tune, and Daryl doesn't know the lyrics, but anyway it's such a good thing to hear this live in 2012!