The Winter Wonder Slam tour featuring Toby Mac, Relient K, Kutless (continuing with the car themes), Stephanie Smith and B. Reith rolls into the Seattle area for a concert at 7 p.m. Saturday (Dec. 12) at Kent’s ShoWare Center. Tickets: $28-$78.

It’s one of the biggest Christian-music tours of the year. And though it was launched by Toby Mac of DC Talk fame, Relient K has been getting much of the attention lately.

Lead singer, songwriter and producer Matt Thiessen has had a banner year on the record charts and is writing songs with singer Katy Perry. The prolific musician produced the hit single “Fireflies” for Owl City. And “Long Shot,” from Kelly Clarkson’s current album, was co-written by Thiessen, Perry and star producer Glen Ballard.

Relient K’s new album, “Forget and Not Slow Down,” made its debut at No. 15 on The Billboard 200 album chart in October. It’s a deeply personal album for Thiessen, who used a breakup with his longtime fiancee as the focus of his songs. The recent single “Therapy” has been a huge hit. You can listen to it on Myspace.

Watch a Relient K interview recorded in September: