I've heard that Aguilera track, Leon Russell's A Song For You, and as Jim pointed out, she has pipes. I always knew that. But I would have hoped that she would leave the (now generic) vocal gymnastics of turning three syllable words into twelve - and hitting 20 notes instead of one at home for a date with Herbie Hancock. Well, she didn't and the result is messy. Herbie says he was blown away. It's pyrotechnics.
Here is the track list for "Possibilities":
"Stitched Up" featuring John Mayer
"Safiatou" featuring Carlos Santana and Angelique Kidjo
"A Song for You" featuring Christina Aguilera
"I Do It for Your Love" featuring Paul Simon
"Hush, Hush, Hush" featuring Annie Lennox
"Sister Moon" featuring Sting
"When Loves Comes to Town" featuring Joss Stone and Jonny Lang
"Don't Explain" featuring Damien Rice and Lisa Hannigan
"Gelo No Montana" featuring Trey Anastasio
"I Just Called To Say I Loved You" featuring Raul Midon