TODAY | April 11, 2014
>> a beloved pop star officially returns to the stage tonight in las vegas . olivia newton john kicks off a 45-night residency, and nbc's joe friar talked to her.
>> reporter: riding in a convertible, olivia newton john 's present is a retro reflection of her past. now begins a new adventure for the 65-year-old legend. why do a show in vegas ?
>> because it's a fun place to be and it's the place everyone wants to be now as an entertainer.
>> reporter: her show was titled "summer nights." this is basically home for you now, right?
>> yes. i love these booths.
>> reporter: her home, the flamingo hotel and theatre in the same intimate theatre where donny and marie perform. we were there as she met up with her band for the first time since arriving in vegas . is this sort of your life story in concert?
>> yes, really. that's a good way of putting it. it's a live journey through my music.
>> reporter: for newton john, that journey started with country music before she was struck with greased lightning .
>> tell me about it, stud.
>> reporter: her star-making turn as sandy paved the way for more hits. let's get physical
>> reporter: the workout anthem "physical" and the musical fantasy film "xanadu." she's rolling all of her songs into the show.
>> people ask me what's my favorite. it's like having a bunch of kids. i don't think you can pick a favorite. you might have a special one that day that's behaving really well.
>> reporter: proceeds from the show will go to olivia newton john 's cancer and wellness center in australia. she is a breast cancer survivor, and last year her beloved sister rona was taken by a brain tumor.
>> i couldn't sing for a while. i was supposed to start here a year ago and i couldn't sing. it was just the first time for me that i ever felt that i couldn't sing.
>> reporter: her sister's love of vegas is what's pushing her to take the stage again.
>> i feel she wants me to do it because she always wanted me to sing, always encouraged me from when i was 15 to do that. so here i am. and yeah, it's going to be special.
>> reporter: she even wore her sister's jacket as she received a key to the vegas strip . that's where super fan deanna got olivia to sign a childhood memento.
>> i had this when i was 10 years old, i'm 43 now, and i still listen to her music all the time.
>> all the time.
>> so we are huge fans.
>> reporter: now those fans won't have to dream of the past anymore. let me hear your body talk
>> reporter: for "today," joe friar, nbc news, las vegas .
>> great to see her. natalie, how bad did you want to be sandy in the '80s?
>> oh, my gosh, i used to skate around my apartment and sing "xanadu" songs.
>> the skating part's fun. it's the singing part with you that is the problem.
>> no question.
>> i was singing throughout that whole piece, i'll just let you know.