The Festival at Mount Si is introducing something new this year, the Big Bend Bash or “B3”,  to it’s opening night schedule.

B3 will feature four young bands, all under 21, in a Friday night show from 6 to 9 p.m. The show is being described as a “free, all-ages, high-energy concert” and promises to be loud.

The band lineup includes LocoMotive (Snoqualmie alternative pop punk), Destination Unknown (Kent, punk funk), Asterhouse (Kenmore, emo alternative rock) and NG (Mercer Island, party rock and blues). Songs will be originals, influenced by the likes of Weezer, Smashing Pumpkins, Foo Fighters, Red Hot Chili Peppers, The White Stripes and Royal Blood.

Gary Horn, B3 organizer, was inspired to put the event together. His two sons, Ryan and Ethan, play in LocoMotive, and he’s watched all of the other B3 bands perform in the past.

“Having kids who are part of the local music network really helps,” he said. “Over the years we’ve watched a lot of bands perform and this lineup was handpicked. These bands are relatively young, but definitely have the ability to create an exciting and memorable experience. Trust me, this is going to be a fun show.”

The idea for a youth-centric concert like B3 didn’t come up in festival planning meetings until May and the event almost didn’t happen at all.

“We realized pretty quickly that a second outdoor music stage was cost-prohibitive. The stage, sound system and people to manage it were just too much,” Horn explained.

Then Minna Rudd, recreation supervisor at Si View, and Jill Massengill, Festival at Mount Si president, came up with the idea of using the Si view Community Center to host the event.

“Within minutes everything else just fell into place” Horn stated. “With a large indoor facility suddenly available, I knew we could pull something great together by August.”

However, the community center has a capacity of only 250, or about 5 percent of last year’s attendance for the Festival at Mount Si, so there’s a real possibility not everyone will get inside for the show.

“That’s a risk that every organizer dreams of, right?” Horn laughs.

Organizers will issue VIP wristbands with entry/exit privileges, first-come first-served, until the show starts at 6 p.m. Wristbands will let people leave and come back as they like, without having to wait in line. People without wristbands will be allowed in until the building is at capacity, and then only when people without wristbands leave.

“We really wanted to retain some space for other festival visitors to come and go throughout the night,” Horn said, but he advises people to come early, for a a wristband.

“If you’re unable to get a wristband, don’t worry,” he said with a smile. “You’ll be able to hear it outside as well.”

Horn hopes to make the event an annual part of the Festival at Mount Si.

“I’ll know B3 was a success if I overhear someone say ‘Oh, you should’ve been there!’ afterward,” Horn said.

For more information, visit www.festivalatmtsi.org or www.bigbendbash.org.