Jason McMackin, bassist for local rock band Total Combined Weight, devised the rock lotto as a way to put on a good show at the peak of the winter doldrums.
The format: Musicians sign up with their instrument of choice, the names go into a hat and bands are formed from selections in mid-December. Each must learn a few designated covers (of the "Since You've Been Gone" variety) and write some originals, and they all play Feb. 21 at the Palace Lounge, 147 W. Broadway.
This year, the proceeds from the show will go toward the Girls Rock Camp at the Zootown Arts Community Center. Organizers hope to raise $3,500 so the 7- to 14-year-old campers can learn on new, instead of borrowed, gear. For more information, go to Missoula Rock Lotto on Facebook.