As with many aspects of the Londoner's red-hot career, the answer is surprising.
"My cousin Gemma is a hairdresser, and when she was studying it, I used to be her hair model. I've got so much hair; I've got the biggest hair in the world!" Adele says in a typically ebullient rush of words. "She kept doing these hairstyles, and I was like, 'No, I don't like them.' I used to go to these hair-styling shows with her as her hair model, and I'd be embarrassed when the judges were walking around and I had these rubbish, normal hairstyles. I was like, 'I've got to find something!'"
So Adele went to a record store and started scouring old LP covers in search of inspiration.
"I saw Etta James' bleached-blond hair and big catty eyes, and I saw Ella Fitzgerald's primped '40s hair, and I just fell in love with them! So I bought these albums -- they were like two for 5 pounds in a bargain bin -- and they were amazing," she says. "I had heard of Ella Fitzgerald, but I'd never even heard of Etta James. But I bought these records and never even gave them to my cousin, because when I heard Etta James, it was like my life was over. She's amazing!"
"Amazing" is a word that Adele uses a lot these days, and with good reason, because there's no better way to describe her meteoric rise. Born in Enfield, North London, her musical talents were obvious early on, and she attended the BRIT School in Croydon -- England's version of the "Fame" high school, which also has produced recent pop phenoms Amy Winehouse, Leona Lewis, Imogen Heap and Kate Nash. On the strength of some demos on her MySpace page, Adele signed to a small English label in 2007. Released the following year, her debut album, "19," took first the British and then the American pop charts by storm, scoring hits with songs such as her indelible second single, "Chasing Pavements."
When the Grammy nominations were announced last month, the tune netted Adele three nods -- for record and song of the year and best female pop vocal performance -- and she also is contending on Feb. 8 for the coveted best new artist prize.
"People keep asking me if all of this has sunk in, but I don't think it ever will, to be honest!" she says with an infectious laugh.
Unlike many of her anorexic peers, Adele is a real woman who isn't ashamed of her curves.
"As long as my boy likes it, I'm fine with it," she says of her plus-size status. "Over in England, it's kind of a bigger issue than it is here, which is weird, because the whole Hollywood look comes from here, obviously, and the whole world kind of follows that. But I feel like I'm taken seriously here: I'm not a celebrity here, I'm a musician, and I don't think it matters what I look like."
This kind of strength and candor is what has set her apart from the pack. Fans connect because they've been there. Like several of the songs on her debut, "Chasing Pavements" was written after the end of a relationship that broke her heart. After a fight with her then-boyfriend, she found herself running down the street at 6 a.m., and she realized she was chasing a shadow that wasn't worth catching.
"When I was writing the first record, even though I had my record deal, it was a small indie in England, and it wasn't a big deal. There was no hype in the beginning," Adele recalls. "I was so consumed with feeling like an idiot in that relationship, it didn't even occur to me that I was going to be putting it down on a record and it could potentially be heard by loads of people. Now sometimes a fan will come up to me and be like, 'Oh, that a------; blah, blah, blah!' I get a little bit like, 'Oh, I appreciate it, but you don't really know about it, and I'm not even thinking about it anymore!'
"But to be onstage in front of like 4,000 people, it's always amazing to hear people sing back lyrics that you wrote in your bedroom when you were feeling like s---. You felt like s--- back then, but you feel like a million dollars now when people are singing back the words that you wrote! It's nice to have a couple of thousand people on your side thinking 'That guy is a p----!'"