For some, creating music is more than a skill, a passion or a mission. It's an affliction they can't and don't shake off, an addiction they embrace and craft into a weekly gig with fellow aficionados and friends.

"It's the one thing I really enjoy doing," saxophonist Tim Powell said.

Drummer Phil Woodring agreed.

"It's the only thing I'm good at," he said. "It's what I live to do."

Powell, Woodring and three other equally devoted musicians make up Groove Affliction, a local jazz jam band with funk influences and an established Wednesday night slot at Zeno's, 100 W. College Ave.

The quintet, which has been together for almost two years, plays vocal-free instrumentals loaded with improvisation and technical dexterity. Several Groove Affliction members are Penn State music majors and most have at least 15 years of experience playing their instruments. All band members also perform in side projects, from university jazz ensembles to local rock acts.

The band, however, doesn't let its erudite skills get in the way entertaining the collegiate masses.

"You're playing for the crowds as much as you're playing for yourself," Powell said. "Even if you have a great artistic statement to make, you've got to fit what you want to play with what the audience is there to hear."

Groove Affliction is up to that task with a setlist composed of half jazz covers, including Charlie Hunter and Medeski, Martin & Wood, and half-original tunes written by Woodring and guitarist Mac Himes.

These original songs are about two minutes long on paper, but live improvisation usually creates eight to ten-minute-long numbers, Woodring said.

"We're afforded a lot of opportunity to be creative with what they've written," bassist Corry Drake said.

"There are specific melodies that we have written out, then the solos and improvisation take off from those melodies. We have three really excellent lead melody players, so I just try to leave a lot of space for them to do their thing."

From the way Groove Affliction discusses "chemistry" and "spontaneous communication," jazz seems more like a relationship than a musical genre.

It is that straightforward honesty between musicians and with audiences that sustains the band's steady gig at Zeno's, saxophonist Matt Claus said.

"The music and the quality of the musicians allows us to be tight in a short period of time, which is a key quality," he said. "The biggest thing we're trying to do is communicate with the audience and feed off the energy of the crowd. Some people dance and some people shout. It all really inspires us to play our best."