On a recent Sunday evening in a tiny storefront in San Francisco’s Mission District, the Pirate Cat Radio Cafe is host to eight members of the Crank Ensemble.

Six musicians sit in a small semicircle around Crank Ensemble conductor and instrument builder Larnie Fox while one waits on the sidelines to be rotated into the group during the next set.

Fox, wearing headphones and manning the mixing board, points to one of the artists holding his “Spring” instrument and makes a cranking gesture. The musician complies.

Out of the instrument scratches the deep sound of metal against springs, which is not terribly surprising when you consider that the instrument’s guts basically are a couple of springs with a wire clothing hanger cranked to rub against them.

Fox then points to another member of the ensemble, one who is holding “Can.” The instrument includes six rubber bands tied to a cat food can, and Fox wants her to pluck them.

Slowly, all the instruments are brought into the piece. Most are hand-cranked, some are plucked, others look like they are being tickled.

The result is an experiment of sound, an art piece that is at times toe-tappingly rhythmic and other times disturbingly chaotic. Some members of the small audience at Pirate Cat Radio Cafe leave politely while others wander in, order a cup of coffee and watch, absorbed in the sound.

“I’ve always been interested in randomness,” says Crank Ensemble’s Fox back at his home garage-turned-studio where he makes the many of the Crank Ensemble instruments. Fox was educated as a painter and he works as program director for Children’s Fine Arts, a program of the Palo Alto Art Center.

After Fox graduated from art school, he immediately started making mechanical sculpture. “If you put a motor (in a creation), everybody likes it — kids, cats, everybody,” he says.

Although he began making mechanical instruments several years ago, he was faced with a problem: The ambient sounds of the motor would be picked up by the microphone he was using.

So Fox decided to make instruments that were human-powered, hand-cranked creations that emit sounds solely from their parts. Those parts are found and household objects like feathers, toothbrushes, scraps of wood, springs and rubber bands. They are amplified by a piezo contact microphone and patched into the mixing board, which Fox uses to control and amplify the sound of each instrument.

The Crank Ensemble debuted in 2005 at the Chapel of the Chimes “Garden of Memory” event in Oakland. Those friends of Fox’s who showed up to crank his instruments for the performance became permanent members of the group, of which there are 16. They are writers, graphic designers, sound artists and Web designers — Bay Area creative types who help promote the group as well as crank the instruments. Most don’t have a background in music, but if you ask them what they do on a night of an ensemble performance, they will tell you they are musicians.

One of those musicians is San Francisco resident Chris Miller, who helps Fox set up and test the instruments before show time. He says he thinks the group performances are “interesting.” “It’s very repetitive,” he says. “You can find some grooves, but it still has an element of chaos.”

The Crank Ensemble essentially embodies the art of experimental noise, a movement of music and art around since the early 20th century, whose commonly-recognized founder, painter Luigi Russolo, made his own instruments and assembled a group of supporters to help play them.

Embraced by some and panned by many, noise is what Fox calls “a painting in sound.”

Bolstered by a wide interest in the group’s work, the Crank Ensemble is planning to tour the Northwest coast and is arranging a European tour. Visit the Crank Ensemble online at www.myspace.com/crankensemble.

Reach writer Laura Casey at 925-952-2697 or e-mail lcasey@bayareanewsgroup.com.