Dec. 9, 2009 -- Pop fans thought they had seen it all -- until they first laid eyes on Lady Gaga. Young, mysterious, androgynous and daring, Gaga charted a record four No. 1 hits this year with her debut album, "The Fame." She has appeared on "Saturday Night Live" with Madonna, won Best New Artist at the MTV Video Music Awards and single-handedly redefined just how far out "outlandish fashion" can be.
Lady Gaga talked with Walters about her skyrocketing career, her family, and what she believes is the biggest misconception about her.
To see what Lady Gaga has to say about her sexuality and more, watch Barbara Walters' "The 10 Most Fascinating People of 2009" Wednesday at 10 p.m. ET.
"I am a songwriter," Gaga told Walters. "I'm a performance artist. I'm a daughter and a sister. You know I don't take my glasses off for, for many uh, interviews but I'll take them off for you."
By age 18, Lady Gaga, born Stefani Germanotta in New York City, was performing in New York nightclubs. Two years later she landed a record deal.
"At 18, thereabouts, you started working in clubs, yes?" said Walters.
"Yes," said Lady Gaga.
"And at one point when you were performing, some of the customers did something you didn't like, and you did what?"
"Well, the name of the club was The Bitter End, and I played there all the time, but I had been gone for a while and it was my first time playing my new glam-inspired music," explained Gaga. "And nobody would be quiet. I walked into the room and before I even opened my mouth they were yelling and chatting and drinking and slamming their glasses, And I, I kept [saying], 'Excuse me, hello,' and nobody would stop. So, um, something just came over me and I, I took my clothes off."
'It Wasn't Really So Easy for My Dad'
"You took all your clothes off?" asked Walters.
"Not all of them..."
"But most of your clothing."
"I left my bra and underwear on."
"You take your clothes off a lot."
"How did your family feel about this child of theirs up on that stage in her bikini underwear?"
"Well, it was, it wasn't really so easy for my dad, especially in the beginning. I mean we didn't talk for months after the first time he saw me play, and uh, he didn't understand. And from a genuine, genuine place, my mother told me that he was afraid I was like mentally unstable."
"Because it was such a drastic change um, from who I was in high school, and who I became."
Lady Gaga attended private Catholic school and briefly enrolled in New York University's arts school before leaving to focus full-time on her performing career. She was signed -- and dropped -- from Def Jam Records at age 19. "The Fame" was released on Interscope records, as was her follow-up release, "The Fame Monster" (November 2009).
"Every bit of me is … devoted to love and art," Gaga told Walters. "And I aspire to try to be a teacher to my young fans, who are -- who feel just like I felt when I was younger."
For the rest of Barbara Walters' interview with Lady Gaga, watch "The 10 Most Fascinating People of 2009" Wednesday at 10 p.m. ET