Jazz guitarist Jack Grassel has long been one of the city's most respected musicians -- on any instrument -- and after a life-threatening illness, he's back on wax (well, on CD, anyway), with a new disc. "Live at The Uptowner," with fellow guitarist Kirk Tatnall and drummer Ernie Adams, is a document from the guitar duo's long-standing residency at the Riverwest corner tap.

Both guitarists play their superaxes -- invented by Grassel -- on the seven-song disc, released by Grassel and Tatnall, who produced and engineered the recording. Based on a six-string guitar, the superax allows a guitarist to also play bass parts at the same time, eliminating the need for a bass player or an instrument with more than six strings.

"I've been playing at The Uptowner now for almost nine years," Grassel says. "I started with the standard guitar, bass and drums trio. Five years ago the bassist quit as I was perfecting the superax. When my friend Kirk Tatnall saw it, he decided to build one also.

"A small number of guitarists all over the world are building instruments with bass capability. We communicate with each other and help each other try to develop this type of instrument. Since everyone plays differently, the instrument of each person is made to enable that person to play the music he needs to play. As a result, each is unique. We guitarists are just trying to do what pianists have been doing for centuries."

It's an esoteric instrument for which Grassel admits, "there is no market," because it is extremely challenging to master. But Tatnall and Grassel are on the same wavelength, Grassel says.

"We have similar opinions about music, so it worked," he says. "In order to have two guitarists in the same band, they have to play at the same high level and be friends. We enjoy each other and play differently enough so that it's interesting for the audience. It's rare to hear that kind of guitar 'fire power' in the same band. You sure don't get that in a one-guitar band. Young guitarists come in and after one set can hardly stand up or talk."

Although more than two dozen drummers have appeared with the duo at The Uptowner, the recording really captures their rapport with Ernie Adams, certainly one of the best drummers this town has seen.

"Yes, Ernie is one of the best," Grassel agrees. "He plays at the correct dynamic, has excellent time, his drums sound good, he reads music, shows up on time, dresses like a professional, doesn't smoke or drink. Our current drummer Sam Belton was a big influence on Ernie."

Interestingly, the seven tunes on "Live at The Uptowner" are all Grassel originals. Excluding standards makes it that rare jazz disc that captures the compositional vision of just one writer.

"I have not played one standard with this band at The Uptowner in the nine years I've been there and never will. That's the rule I have," says Grassel. "We have a book of 60 of my compositions that we perform. I (do) play standards on other gigs. Wayne Shorter, Horace Silver, Cecil Taylor, Thelonius Monk and many others only play just their own tunes. I think everyone everywhere should just play their own tunes. Music would be much more interesting than it now."

With disc in hand, Grassel is moving forward musically rather than focusing on marketing himself or the record. So, don't expect to see billboards advertising it.

"My goal for the CD has been completed," he says. "(It) was to document the amazing thing we do at The Uptowner. Music is what matters. I'm too busy trying to play the guitar at a high level and play meaningful relevant music than spend my time promoting myself."

"Live at The Uptowner" is available via the Jack Grassel Web site, jackgrassel.com or from Grassel at The Uptowner, where he and Tatnall and drummer Sam Belton perform on the third Sunday of every month.