Several performers are kicking off a worldwide tour in Lincoln Monday night. It is the first of 190 stops for the "Squeaky Wheel Tour," which brings attention to missing children and adults.

The tour opens at Duggan's Pub, the same place where Lincoln singer-songwriter Gina Bos was last seen six years ago.

A year after she disappeared, Gina's sister Jannel Rap started an organization called GINA, whose mission is to bring together media agencies and artists to create hope and awareness for missing people.

"There are moments when it feels like the first day," Rap said. "In general, I wouldn't say it's easier. It's--you come up with a coping mechanism to deal with it."

Six years ago, Gina Bos finished playing at Duggan's at 1:00 a.m. and then left. She has not been seen since. Police found her car outside the bar with its trunk open and her guitar inside. Bos's friends say she would never have left without her guitar.

"No, I don't think she would have left her guitar," friend and co-worker Marilyn Borman said. "Especially in an open trunk for somebody to take. She loved her guitar. She brought it to work."

Another friend, Sharon Plautz, says Gina had more than just music going for her. Plautz says her friend would never have left her family behind.

"Mostly, I remember that she was very close to her children, and she talked about them often," Plautz said.

Friends and sisters insist that someone must know what happened to Gina six years ago.

"They're just too afraid to come forward, or they've buried it so long they don't want to talk about it," sister Tammy Smith said.

The first stop on the Squeaky Wheels Tour will end at 1:00 a.m. Tuesday morning, the same hour Gina disappeared six years ago. The concert will be shown live on the web, starting at 8:00 p.m. To view the concert, or to make a donation to the organization, click here.