MUSIC SID AND NATHAN WILLIAMS : Zydeco Zip : Two Louisiana brothers bring their ‘French and English jumpin’ music’ to Santa Barbara.

You’ve probably never heard oC. Hammer’s brother, M. C. Hacksaw, or Madonna’s older sister, Lasorda, or Mick Jagger’s brother, Joe Bob, or Steve Winwood’s brother, Bubba, or Morrissey’s brother, Manny, or Boy George’s twin sister, Girl George. These are the behind-the-scenes siblings. But, of course, I’m just kidding.

All of this somehow brings us to Sid and Nathan Williams, a couple of brothers from Lafayette, La. Nathan is the front man for Nathan & the Zydeco Cha Chas, and Sid is, well, Sid.

Sid owns Sid’s Market, sort of a little corner Mom-and-Pop store in Lafayette. Nathan, the musician, works there. Imagine Sting working at his dad’s carwash. Anyway, across the street is El Sid-O’s, a nightclub. Guess who plays there all the time? No, it’s not Sting. Nathan’s first couple of singles were released on Sid’s own record label, El Sid-O Records.

Everything’s coming up Sid, it seems. Except for Nathan, who’s coming to the Golden State as the Next Big Thang in zydeco, doubtlessly trying to sell you a copy of his new one, “Your Mama Don’t Know.” He’ll be at Felix’s Cantina in Santa Barbara on Tuesday night. So what else is there to do? The NBA can’t last all year.

“I haven’t gotten a nickel off the new record yet,” Nathan said on the phone direct and all the way live from Sid’s.

“I’ve done weekends in California before, but this time we’re doing two weeks and two days on the West Coast. I do real good down here, but sometimes you gotta take it on the road. I’m trying to promote my album, and that’s how you do it.”

But just suppose it’s a really busy week in the grocery business--the new flyer just came out--and Sid won’t let Nathan off to tour. Nah, probably won’t happen.

“My brother and I are a team,” Nathan said. “He had the money, and I had the talent. He released my first two 45s--I’ll probably bring some of them when I come to California. They’re probably pretty hard to find out there.

“Sid used to take me to see Clifton Chenier; I used to see him all the time. That’s when I decided that zydeco was the type of music I liked. And later, Chenier sold me my first accordion. Anyway, Sid got me started about three or four years ago, and I help him out at the store.”

And unlike these rock stars who inevitably spoil the momentum of their live shows with the sensitive (and really boring) ballad, Nathan doesn’t do a lot of slow ones, but mostly Warp 10 zydeco rave-ups that keep the dance floor packed.

“It’s French and English jumpin’ music,” Nathan said. “You can’t sit down and listen to it--you’ll be dancin’. And if you’re not dancin’ on your feet, you’ll be dancin’ in your chair.”

There may be a tradition to zydeco music but Nathan says his music, although influenced by others, is very much his own.

“I like Buckwheat Zydeco a lot, but what I do is my own style. Most of my songs are original. They come from me. I play a little bit of everything. We can probably do about 40 songs and not repeat anything. You just can’t stay in the same rut or you’ll die out. You’ve got to be progressive and experiment.”

And yet if zydeco is as good as Williams and his fans think it is, why is it just Guns N’ Roses and Madonna appearing in every other video on MTV or on the cover of every magazine every week forever? Maybe most people probably think that zydeco is some obscure tropical disease that they probably don’t want.

“You know, I figure a lot of people have never caught on to zydeco. But one day, it’ll happen, and I hope I’m still playing when it does. I’m just going to keep going as long as I keep my health.”

* WHERE AND WHEN

Nathan & the Zydeco Cha Chas at Felix’s Cantina, 525 State St., Santa Barbara, 962-1432, 8 p.m., $8. (Also appearing at Alexander’s in Ventura on Monday night.)