"We had such a great time with it the last time that we just had to do it again," said Kristen.
The popular ABC soap opera is airing its second music-centered storyline, focusing on its younger actors.
"It's their senior year. We're graduating so there is a lot of drama with a lot of characters," said Kristen.
There is so much drama that it will take three episodes to cover it all. Kristen Alderson is front and center for all the fun.
Her real life brother, Eddie, is also on the show, but they don't play siblings. They don't often share scenes as well. But for this year's musical, Eddie's character is old enough so he did get to take part.
"Last time I was off-set watching them and I was kind of jealous," said Eddie. "Now I'm actually involved and it has been fun so far."
Kristen has been on the show since she was 6 years old. She is now 18, and it's because of her that 15-year-old Eddie joined the show in 2001.
"We are each other's biggest fans, and he makes me crack up more than anything," said Kristen. "We were filming scenes together the other day and we felt bad because we couldn't keep it together."
Eddie says he appreciates his sister's support in helping him get into the business.
"She would be the first person I would thank," said Eddie. "At first I didn't want to act, but they needed a new boy on the show. She had been on the show for a couple of years before me. I was friends with everyone on the show so I tried out."
"One Life to Live's" musical begins Friday at one 1 p.m. on ABC7.