Major Chords : Mary Kay Fishell of the Convertibles has a voice that’s so powerful it could rival the noise at Dodger Stadium after an L.A. home run.

Ain’t no junk cars. Ain’t no Edsels. Ain’t no Yugos. Ain’t no Corvairs. Ain’t no Pintos. These Convertibles are cruising along smoother than a Mercedes on the autobahn. These Convertibles are also a real working band--they have gigs and actually play somewhere every week.

But forget that--let’s get right to the important stuff. The Dodgers. Group leader and lead guitarist Mike Fishell is such a hard-core Dodger fan that he wears a Brooklyn Dodgers cap to most of his gigs. Needless to say, the band won’t be playing during the second week of April--it’s the Dodgers’ 1991 home opener.

“World Series bound,” Fishell said. “That’s the way I feel. Usually, the Dodgers win with pitching, but this year they’ll hit their way into the Series.”

But louder than the crowd at Dodger Stadium after a Blue Crew grand-slammer is Convertibles’ singer and Fishell’s red-haired sister, Mary Kay Fishell. Her voice is so powerful it registers on the Aretha Scale. If she and Marjorie Extract of J.D.’s Last Ride ever did a duet, no window in the 805 area code would be safe.

When the band plays live, Mary Kay Fishell usually sings about half the songs--lots of Aretha, Patsy Cline numbers and other country-tinged rockin’ blues tunes for which a female voice is paramount.

“About six years ago my brother Mike was in a band called the Reverbs,” Mary Kay Fishell said. “They broke up and he asked me what they should do and I said, ‘Put a band together and let me sing.’ ”

That’s exactly what they did. In the beginning it was a band of four, then singer/musician Steve White joined four years ago. And things seem to be working out fine for the siblings. “I always knew she could sing,” brother Mike said, “but I never knew she could wail. Besides Mary Kay, we also have Steve White--there aren’t any better two singers. I’ve got the two best singers in any band.”

White is a busy guy--he plays keyboards, guitar and sax, plus he sings about half the songs in the Convertibles. With a voice reminiscent of David Hidalgo of Los Lobos, White can more than hold his own on Ritchie Valens, Otis Redding, James Brown and even Jackie Wilson songs, no mean feat.

“I’ve always liked Clyde McPhatter, Jackie Wilson, Freddy Houston and guys like that. I’m also kind of a world beatnik and I like a lot of reggae. Sometime in the ‘90s, we hope to make a tape.”

Whenever the Convertibles play, people dance--a lot. And they’re expected to dance a lot at the Keynote Lounge in east Ventura, where the band will perform Friday and Saturday nights.

“We definitely have a wide variety of music,” Mike Fishell said. “We do some hard-core country, some rock ‘n’ roll, some soul, some rhythm and blues--we pretty much play whatever we want. Plus, we have a set of originals. We always have just one more song.”

And playing in a band in a bar is not so much a job as an adventure. If the most exciting thing you’ve ever done is whistle in the back yard, then bands in bars might be too much for you. “There’s at least one drunken nut every night,” White said. “But there are degrees of drunken nuts. There’s the guy in the back that yells, then there’s the guy that gets in your face and yells.” Which makes it sound like some of the most dangerous work around. But apparently not.

“Nothing,” Fishell said, “tops the time we played a wedding and the bride and the groom got into a fistfight on the dance floor.”