They’re talented, they’re in demand and they’re the featured band Sunday at Harmony on the Harbor, Washington’s free concert series in Festival Park.

K-OS (pronounced “chaos”) has developed quite a local following in the past year, since the four band members first started jamming together. While their rock repertoire — mostly cover songs spanning many decades and genres — may come as no surprise, the band’s youth definitely does. The four-piece band is comprised of two guitarists, a bassist and a drummer, none of which are over the age of 14.

But age doesn’t really matter when it comes to rocking out to Lynyrd Skynyrd and Wheezer. Connor Smith (14), Greyson Schmitt (14), Kendall Smith (11) and Caleb Petty (13) have an appreciation for classic rock and have been sharing it at venues like Backwater Jack’s, the Aurora Fossil Festival and private parties across the county, according to Jennifer Schmitt, Greyson’s mom.

A year ago, K-OS got its start at Washington’s Second Baptist Church, where Greyson, lead guitarist, and Caleb, K-OS’s drummer, played in the worship band. Their classmate Connor soon signed on with lead vocals and guitar, and with him came his younger brother Kendall, the band’s bass player, Schmitt said.

According to Schmitt, their talent, however, isn’t limited to cover songs.

“They also write their own music,” Schmitt said. “The have four songs that have been professionally recorded and copyrighted and you can download them from iTunes. They have a few more they haven’t recorded yet.”

K-OS gets together and practices as much as they can, but with vacation schedules in the summer and sports schedules during the school year, Schmitt said that usually works out to once a week. But their love of music and playing together means they’ve got their parts down pat.

And as for K-OS’s growing fan base?

“Just because of their ages, it makes it interesting,” Schmitt laughed. “They’re humble. They don’t realize what’s going on.”

K-OS takes the stage at Festival Park at 2 p.m. and will play until 4:40 p.m. Sunday.