Every once in awhile, an artist in an established band will make a side-project that turns out to be more successful than the musician's main group.

Such is the case, apparently, for Andrew McMahon. The piano-playing frontman of the alt-rock outfit Something Corporate started the side project Jack's Mannequin in 2004 during a break from his other band's committments. While Something Corporate put out good music, Jack's Mannequin was even better. The songwriting was more personal and the songs had a little more edge.

"I experienced a little bit of a renessance as a song writer," McMahon said of the writing process that would become Jack's debut, "Everything in Transit." "I was writing songs and recording songs like I always do, but now without a safety net. It was very free and very inspiring — one of the most inspired times of my life and as a musician.

"I maybe embraced the idea of being a little more specific and personal. There wasn't anyone standing around saying that wasn't the right thing to do," he said.

McMahon will be in Park City this week as one of the performers for the Warner Bros. Records' three-night tribute to the union of music and film. "Where Music Meets Film: Live from The ZonePerfect Bar," will feature up-and-coming artists along with big name performers, such as Josh Groban, Michelle Branch and Jason Mraz. Each will perform accoustic sets at Harry O's. The shows are all private but portions can be seen on FUSE Feb. 4 during a one-hour special.

McMahon spoke to the Deseret Morning News recently from his publicist's office in New York. He had just come from snowy Virginia and planed to take a quick trip to Costa Rica before heading to Utah.

For McMahon, being at Sundance is an appropriate match. The singer also has a documentary he hopes will be picked up and shown at one of the other film festivals this year. When McMahon jumped into the Jack's Mannequin project, he decided to film the process. What no one could have imagined happening was he was diagnosed with acute lymphocytic leukemia while making the record.

"The idea (for the movie) was one that found me rather than I found it," he said. "On our very first tour is when I got sick. I had the camera with me. I had been using it as a video diary to some extent since way before I got sick. My inclination was to keep documenting the process of my life that I had been documenting before that."

In a way, continuing to film while he was sick was therapeutic, McMahon said. He admitted that when the cancer was at his worst he "lost my vibe to pick up the camera." But after he made a full recovery, he told two friends who were filmmakers that he had dozens of tapes of him both before and after he was sick. His friends proposed the idea of turning it into a documentary. McMahon agreed.

"It was like I was obligated to share this experience," he said.

McMahon hopes his film can be a source of inspiration and hope to other cancer patients and survivors.

In addition to the film, McMahon also has a new Jack's Mannequin album coming out later this year.

"The style is pretty dramatically different in some respects," he said. "It sounds a little more of a band record. The last one was so piano driven. I was the only band member at that point. I put simple drums and guitar over it and built upon simplicity. There are more ambitious arrangements on the new record."

E-mail: preavy@desnews.com