Chemistry: One Part BoDeans, One Part Sam Llanas : Roots rock: The musician says years with the group haven’t changed his makeup, just allowed his evolution as a lone element.

The roots-of-rock trend of the ‘80s, while vital for a time, didn’t leave many lasting artists in its wake. Long gone from the scene are such twangmeisters as Rank & File, the Bangles, the Georgia Satellites, Lone Justice, Green on Red, the Long Ryders and any number of bolo-tie sportin’, Gram Parsons-worshiping “cow punks.”

The BoDeans, who entered the national spotlight relatively late in the game, are one of the very few groups from that era still working. The band from Waukesha, Wis., has released five albums since its debut in 1986 and has shown solid artistic growth. Its sound does seem somewhat anachronistic in 1995--although that’s not necessarily a bad thing.

In any case, after a dozen years of playing the same style of music with the same group, BoDeans singer/songwriter/guitarist Sam Llanas says he is feeling the urge to spread his creative wings and move in different directions. He will perform solo Saturday night at the Coach House in San Juan Capistrano; it will be his first appearance in Southern California without his band mates.

He hopes that it will be more than just a “what the hell, why not?” type of affair and that it will signal the beginning of a successful solo career, although he claims to have no intention of leaving the BoDeans completely.

“I’m gonna start doing more and more stuff on my own, just because I think it’s time,” he said during a recent interview. “I want to have another outlet to do some other things. Over 12 years, I’ve accumulated enough songs that we haven’t done in the band that I want to put out my own record and get that out of my system.

“It’s hard being in a band,” he added. “It’s a democratic thing. I like doing things myself because you can do anything you want at the spur of the moment. You don’t have to think about it. If it flops, well, so what? And if it goes, then great.”

Though enthusiastic about the project, he was vague about direction. He said he’d be doing new originals, some BoDeans songs and a few covers but didn’t want to get into the specifics, nor did he want to talk about the BoDeans, who will be recording their next album in the coming months.

The music he’ll play at the Coach House “can’t be that much different than what people are used to from me, because I’m the same guy that’s in the BoDeans,” he noted. “I’m not gonna start playing the tuba or anything. I would like to have a moodier kind of atmosphere than the BoDeans have--kind of like Chris Isaak moody, something like that.”

He said he selected the Coach House for his coming-out show because he likes the attentiveness of the crowds it draws.

“It’s a great place because people come there to listen to music. I didn’t want to do this in a crowded little bar where people would be indifferent to it. They can get louder than you are in a situation like that. I want to play for people who are willing to listen and not talk.”

* Sammy BoDean, a.k.a. Sam Llanas, Two-Way Street and Lost Inasense play tonight at the Coach House, 33157 Camino Capistrano, San Juan Capistrano. 8 p.m. $13.50. (71 4 ) 496-8930.

* Sam Llanas plays tonight at the Coach House, 33157 Camino Capistrano, San Juan Capistrano, between sets by Two-Way Street and Lost Inasense. The music starts at 8. $13.50. (71 4 ) 496-8930.