Since his start in the late 1970s on the Los Angeles creative improvisational music scene, guitarist Nels Cline has moved among avant-garde jazz, noise rock, and crepuscular ambient sound. He may be best known for joining the alt-Americana ensemble Wilco in 2004. But his wide-ranging explorations continue, including Brazilian esoterica and dissonance with the CD Macroscope by the Nels Cline Singers.

Cline has an especially close relationship with Mark Christman's Ars Nova Workshop (ANW), Philadelphia's premiere booker/presenter of undefinable musical work. Since 2000, ANW has brought adventurous progressive music to this city. Cline has visited no fewer than 10 times, according to Christman, in 14 years.

"Nels is one of those musicians who embody ANW and is on a short list of artists that inspired me to start ANW," says Christman. We've had solo Cline, the Celestial Septet, an outfit titled Unfold Ordinary Mind, the Nels Cline-Toshi Makihara Duo, Electric Ascension, Gregg Bendian's Interzone, the Nels Cline Singers, and others. And on Friday, ANW and Cline's Singers join forces again at Johnny Brenda's.

Christman calls John Coltrane and Miles Davis guiding forces. In the 1990s, he traveled to New York to see groundbreaking figures like John Zorn, Tim Berne, and Cline, "folks drawing connections with aspects of other extreme music."

Cline, too, calls Philly-born Coltrane a shining example of nonpareil musicianship and artistic restlessness serving great artistic visions. "Coltrane transcends the saxophone while pushing it to a super-cogent level of pure saxophone-ness," says Cline. (In 1999, Cline released Interstellar Space Revisited, in which he reconfigured the beauty of Coltrane.) "Like the masters of Indian classical music I admire, Coltrane's a beacon of excellence on all levels: expressive, creative, technical, and intentional."

Has his Wilco work affected his other projects (and vice versa)? Cline says he doesn't know. "Each project has its own qualities, parameters, paradigms," he says. "Maybe had I not been in Wilco I would not have felt the impulse and/or freedom to write that repetitive coda to 'The Wedding Band' on Macroscope - who knows? Then again, that song's 6/8 groove is un-Wilco and un-Americana."

Cline says that, just as he did 25 years ago, he writes what he hears, what sounds good, and what provides fun, coherent ways to team with collaborators: "I follow my instincts and try not to compartmentalize. In the past, when I carved it up and endlessly analyzed, I became so stressed I almost quit playing. Not good for me."

What is good for Cline is working on Macroscope with his wife, Yuka Honda, cofounder of Cibo Matto and partner in the noise-pop duo Fig. "I wanted electric piano, and she can do it. She doesn't see herself as an improviser per se but has the ability to improvise in a 'non-jazz' way, and her sensibility about harmony, sound, groove, and production set her apart as a significant artist of great worth - he said as though objective."

Macroscope is a rich embrace of Braziliana, balladry, percussion, and the tender-touch influence of samba master Baden Powell, who "made me feel less sheepish about using my voice," says Cline. "I think my vocals add intimacy and even romance, even when it's a bit wobbly."

Then there's Ars Nova, through which Cline has gladly premiered many of his works. "I want to work with any such quixotic cultural organizations," he says, "who offer me these opportunities rather than me going to them, and ANW really keeps track." Cline says ANW is one of few such organizations still operating in the "culturally impoverished U.S. of A." Funding can sometimes be tough. But Philly always has been welcoming: "It has serious history, I have good friends there, and just try to play wherever and whenever possible, period."


An Evening with Nels Cline

9 p.m. Friday at Johnny Brenda's, 1201 Frankford Ave.

Tickets: $15. Information: 215-739-9684 or www.johnnybrendas.comEndText