"It's thrilling to hear her sing!" exclaims Rick Rubin. He's talking about Sugarland vocalist Jennifer Nettles, whose first solo album he's in the midst of producing. Rubin – who has worked closely with Red Hot Chili Peppers, Johnny Cash, Tom Petty and the Heartbreakers, Beastie Boys, Linkin Park, Adele and many others – clearly knows talent. And it seems the admiration is mutual on Nettles' end as well.