With singer and guitarist Mike Ness serving as its sole constant, Los Angeles-based punk band Social Distortion has spent more than 30 years delivering a hard-living mix of tunes drawing from blues, country and rockabilly. Regularly treading the line between the rebelliousness and brashness of the Clash and the prison-bound toughness of Johnny Cash, the band still favors its middle finger when it comes to a musical salute. Supporting the release of its most recent record “Hard Times and Nursery Rhymes,” Social Distortion is scheduled to bring greasy-haired, punk-rock grit to the National on Wednesday, May 18, at 7 p.m. $28-$33.