In today's high- tech world, branding means everything. Ironically, one of the most reliable and identifiable music venues in town regularly hosts bands that draw their influence from the precomputer age. For those with a hankerin' for some alt-country, folk, or rockabilly, everyone in Seattle knows to head down to Ballard's homey Tractor Tavern. This weekend, the Tractor plays host to something special: The 16th Annual Shake the Shack Rockabilly Ball, with KEXP's Leon Berman as the Master of Ceremonies. Thursday spotlights the ladies with an all-female rockabilly showcase, and Friday and Saturday's bills both feature floor-stomping swingers from as far away as Denmark and Sweden and as close as the practice spaces in old industrial Ballard. Head out early to enjoy the Rooks Car Club Hot Rod Show, taking place in front of the venue during the afternoon in tandem with more live musicrockabilly, we presume. $10 advance, $12 at the door. 5213 Ballard N.W., 206789-3599.