Ford Is on the Right Track With the Blue Line : The jazz guitarist, who plays with his band at the Coach House tonight, says the simple, powerful format is right for the moment. His next musical destination is unknown.

Trying to categorize the musical style of guitarist Robben Ford isn’t always easy.

Blues, jazz and rock are the three basic genres that Ford has played zealously, and authentically, during a prolific 20-plus year career. And in the course of that career he’s worked with such eminences as trumpeter Miles Davis, singers Joni Mitchell, Rickie Lee Jones, Jimmy Witherspoon and Charles Musslewhite, and bands L.A. Express and the Yellowjackets.

But tonight the focus should slightly narrower, as Ford appears with his blues-driven trio, the Blue Line, at the Coach House in San Juan Capistrano.

“The blues is our springboard,” said Ford. “That’s where we’ve started,” he said referring to the threesome that also features Roscoe Beck on electric bass and Tom Brechtlein on drums. The group, in which Ford plays electric and acoustic guitars, has made two albums on Stretch Records: 1992’s “The Blue Line,” and the just-out “Mystic Mile.”

Those recordings are steeped in the blues, a song form that Ford reveres for its “simple truths.”

“There’s a kind of rawness, a real direct experience of pain, pleasure, joy, sorrow,” said the guitarist, 37, in a phone interview from his home in Los Angeles. “The blues is not conceptual, not fuzzy, not in the realm of thought. It’s direct and very vital, and since it’s not complicated, everybody can get it. It’s all about a feeling.”

But the albums contain more than blues numbers, from such funky, James Brown-inspired numbers as “Busted Up” to the tender, lyrical “Trying to Do the Right Thing,” a paean by Ford to his wife of seven years, Annie.

Ford said he feels it’s essential that he chart a broad course now. “I don’t do one particular thing,” said the guitarist, who speaks openly in a gentle tenor voice that is mirrored in his singing. “I need to have the opportunity to grow in whatever direction music takes me.”

His present interests are rhythm-and-blues numbers and songwriting in general (he cited “Trying to Do the Right Thing,” which is included on “Mystic Mile”). Making the two Stretch recordings, he said, has enabled him to pursue new musical ideas.

“Records are so important these days. In order to work, you’ve got have to a record out there. And a record gives you the chance to establish a direction, and set on a road from which you can grow, so what it is that you do can change.”

Beck and Brechtlein, who have been playing with Ford in different configurations for 10 and six years respectively, are ideal foils, the leader said.

“We all have broad musical backgrounds, and that combination of their being versatile, coupled with our strong personal relationship, makes the trio very musically creative,” Ford said. “We’re good for each other. It’s like a marriage in that we have our struggles, and our good times, but, all in all, we realize that we work well together, and make good music.

“We function as a family, as opposed to being transients that come and go. Good, versatile musicians are hard to keep together, but somehow we all want to accomplish the same thing, which is having a band that plays music we really enjoy playing so that we can communicate to an ever-growing audience.”

Ford used to perform with quartets and quintets, augmenting Beck and Brechtlein with keyboardist Bill Boublitz and saxophonist Bob Malach, who make cameo appearances on “Blue Line” and “Mystic Mile.” But a tour in 1989, for which the group was stripped down to a threesome for financial reasons, convinced him that less was indeed more.

“After the tour, I said, “Guys, this is the band!’ ” Ford recalled, laughing softly. “And they agreed. We discovered something with that simple format that was a lot more powerful and immediate. When it’s at its best, it’s better. There’s more space, more simplicity, and I’m kind of a minimalist at heart.”

Asked if the current format of blues, R&B; and slow ballads is where he wants to be for the moment, Ford said, “Yes, absolutely.” Then he hedged. “Where that’s going to go next, I don’t know. But I can guarantee that it will change.”

* Robben Ford and the Blue Line play tonight at 9 at the Coach House, 33157 Camino Capistrano, San Juan Capistrano. $17.50. (714) 496-8930.