Bluegrass band Mile Twelve of Boston (above) will team up with Roots band Low Lily (right) of Vermont for a double bill at Camden Opera House on Friday, March 29, at 7:30 p.m. Both bands formed in 2014 and grew out of the Boston acoustic music scene. General-admission tickets — $14 in advance, $16 at the door — are available at camdenoperahouse.com and at the door one hour prior to the start of performance.