The Ontario Theater held something close to an American roots rock festival last night. Three tradition-minded acts, Kristi Rose and the Midnight Walkers, The Leroi Brothers and the Blasters, tore through sets of classic rock 'n' roll, boldly asserting the music's country, R & B and rockabilly heritage. If the headlining Blasters clearly offered the evening's most dynamic and original performance, the two opening acts conceded nothing in terms of pure physical energy.

Appropriately, the Midnight Walkers kicked off the evening with a wild rockabilly rendition of "The Battle Hymn of the Republic." This New York trio's nasty rock 'n' roll was granted a dramatic theatricality by Kristi Rose, who shook her ample body all around the stage. There was no doubt that Rose's erotic nasal delivery, all honey purrs and growls, was a show-stopping instrument, and on Patsy Cline's "Crazy," she mesmerized the crowd.

Texas' Leroi Brothers lived up to their title as the kings of "trashabilly" as they served up a rabble-rousing set of rockers heavy on energy and light on finesse. With local boy Evan Johns picking out chaotic guitar lines, the band played country-fried rockers, garage classics, instrumentals and originals that got most of the crowd out of their seats and dancing. The band was distinguished by Joey Doerr's swaggering, hip-swiveling delivery and Steve Doerr's contagious originals like "Pretty Little Lights of Town."

It wasn't just the Blasters' superior musicianship or tight ensemble play that set them apart from the earlier acts. In Dave Alvin, the Blasters possess not only a fiery guitarist, but one of rock 'n' roll's most evocative songwriters. With brother Phil Alvin spitting out the lyrics in his tense, clipped vocal style, the band roared through a powerful set of Alvin originals and covers.

Particularly impressive was the Blasters' treatment of Alvin's scathing political commentary, "Common Man," and his Hank Williams eulogy, "Long White Cadillac." A steadier or tougher rhythm section than the Blasters' can't be found, and with Gene Taylor laying on the boogie-woogie piano and Lee Allen adding classic New Orleans saxophone, the band created rock 'n' roll that added up everything good from the music's history and then some.