Transcript for Why Sia, a Pop Song Mastermind, Shies Away From Fame
. Sia has worked with the biggest bold-faced names in the business, from beyonce to Katy Perry, but yet when it comes to her own hits the singer makes some unusual choices to the clothes and the hair. And why she doesn't want to show her face, here is ABC's Chris Connelly. Reporter: This incredible voice has gone up to the top of the pop chart. The voice of Sia furler, who has chosen not to show her face on camera when she performs live or speaks to the media. You don't really do entertainment stories really that much, right? Sia, not like this, I don't. What makes this the right decision for you, to turn your back away from the camera? Well, I don't want to be famous. Or recognizable. I don't want to be critiqued about the way that I look on the internet. And I was at target the other day buying clothes and nobody recognized me. And my song was on the radio. And I'm like okay, this experiment is working. Reporter: With this gifted dancer, her song, chandelier, helped enter the charts at 41. What was the reason? I guess because it has a dark undertone. ? ? ? sad, right? She has posed on the red carpet with her fiance. But Sia has been face to face with full-on celebrity and it is not for her. I have been writing songs for pop stars for a couple of years and become friends and seen what their life is like. And it is just not something I want. Sia has spent the last few years6zcñ becoming one of pop songs freshest artist. Beautiful like diamonds. Rihanna's "Diamonds." "Wild one". Yeah, I heard you were a wild one. How come did it take you to write "Titanium"? It was like around 40 minutes, I think, and then maybe half an hour to record the vocals. That is amazing. What gets you started on the lyric? Well, I usually choose a one solid focus. Like a chandelier, and I think how can I use that? That is a strong title. Some songs pass through more than one artist's hands before it gets a title, take the song, pretty hurts. I sent it to Katy Perry, and then probably Rihanna and beyonce's people. And Rihanna just threw the money down. It was a really awkward situation. So Rihanna's engineer had a great idea. He was like why don't you play her "Diamonds." Rihanna was like, I love this song. It's mine. Everybody goes, so I'm happy? Yeah, that is how we like it here. Why then step out and become an artist again? I didn't think this music would get heard otherwise. Reporter: In 2005, this Australian native song was used in the finale of "Six feet under." ? ? I was extremely depressed at the time. That was one of my lowest points. It was not just alcohol for you, was it? Oh, no, I don't think I would have ever started drinking if I hadn't gotten hooked on zanax and oxycontin. She holed up in her home, thinking about suicide. Eventually she found her way to a program. I thought oh, my god, that was what was wrong with me all along. Sia took is downstairs, as we watched and listened, Sia began to melody right there on the spot. ? ? ? ? So then that is all we would do. That was -- can we have a copy of that? Nice work. And Rihanna cuts it next week. How often do you tweak it? Oh, I don't tweak it really at all. I can make any word fit. Like chandelier, so if you bend them in certain ways? The repetition of a strong concept is how these two came up with the song, perfume. We write these songs in like 40 minutes and then just send them to someone, and never really refer back to them again. It passes through your life in an afternoon? Do I see you there ? ? you'll be me ? you and me ? ? ? sometimes ? ? I just lift these concepts off like crap television. And then like, it's so fun. And I apply them to music. That is why we love this pop music, though, isn't it? Yeah, because it gets -- there is a story or it makes us feel good or it makes us feel sad. Oh, but the odds of the public getting to listen to Sia is not good. As she told us upstairs, touring is not on her menu. I mean, I did imagine it. But I have unimagined it. It may change, but right now that is not on the cards for me. She has performed on such shows as the Ellen DeGeneres show, and Sia notes this is part of the concept. The concept of you know, creating a brand which is an inanimate object, this blonde bob, being able to put anyone under it, a kid, a man, a dog, and then everybody can be the singer. She is a very awesome singer, very caring. And she did jimmy Kimmel. Years ago, the family friend from the Australian band "Men at work" introduced her. He said I hope you're happy and successful. Are you? Yeah. Can you believe it? I do spend a lot of time like pinching myself. I have to say it has been pretty amazing, I might cry. It has been really amazing. The last couple of years have just been, since I made the decision to just take care of my own sanity and serenity, my life just improved so much. And I'm honestly surprised that things are working out so well for me. I'm Chris Connelly for "Nightline," in Los Angeles.
This transcript has been automatically generated and may not be 100% accurate.