Making pure music is a lot harder than it seems, which is why so few musicians attempt it. Absolute devotion to your chosen idiom is a must, of course, but it also helps to stick with a form that values tricks over substance. On last year’s full-length release, The Further Adventures of Los Straitjackets, the Nashville quartet proves their undying devotion to garage rock ‘n’ roll, and do it all in a quick 30 minutes. The guitars of Eddie Angel and Danny Amis evoke biker films and beach movies, Link Wray and Dick Dale, while such compositions as “Cal-Speed” and “Teen Beast” add tricky harmonic twists and plenty of interesting incidental matter to surf music’s mutated blues licks and mock-wistful melodies. On their latest tour, Greg Townson replaces the ailing Amis — still, the men in the Mexican wrestling masks continue to seek the elusive instrumental breakdown of their dreams.