Dave McKenna plays the piano like a grounded angel. His melodies, his touch, and his dreamier tempos often suggest an empyreal provenance; but his left-hand chords and stomps remain delightfully earthbound, imperturbable in their rhythmic accuracy, inexorable in terms of swing. Actually, you can find entire rhythm sections less propulsive than McKenna’s left hand. His walking (at times galloping) low-register lines might serve as models for aspiring bassists, and when he launches into a hefty stride pattern those lines constitute part of a decent drum set as well. McKenna mostly records and performs as a solo pianist–as he has on his last two visits to Chicago–for the simple reason that he doesn’t really need any help.

But this weekend McKenna will share the billing with the instrument he’ll play. While McKenna treks in from his Massachusetts home, a specially outfitted truck will head down from Madison, Wisconsin, transporting the piano: a century-old Steinway Model C that boasted a remarkable sound even before its recent, compulsively detailed restoration–a restoration undertaken specifically so that McKenna might play it.

Dave McKenna, meet the Voice of God.

That’s what they call the piano up at Farley’s House of Music in Madison, where Timothy Farley, a veteran piano technician and sometime jazz DJ, first obtained it four or five years ago. At the time, it needed just about everything: new strings, new tuning pins, repairs to the soundboard, and serious veneer work. “But even in such poor condition,” recalls Farley, “someone up here heard the sound and said, ‘That’s got to be the voice of God.'”

What makes this piano so special? you might ask. “How much time do you have?” Farley might reply, but he’d probably start with the size. The Model C, whose design dates to the Victorian era, measures seven feet four inches from front to back–roughly a foot and a half shorter than today’s top-of-the-line concert models. At the time it was “the largest solo instrument Steinway made,” explains Farley. “Steinway did make an eight-footer–the predecessor of the full nine-foot instrument made today–but that was mostly for use with an orchestra. The thinking was, the Model C would have been the kind of all-around piano you’d use for playing chamber music by Chopin, Schumann, Beethoven; and if you played a concerto for full orchestra, you’d want to use the larger instrument developed for that.

“But today we’ve sort of lost that aesthetic. People always want the biggest, the most powerful. So although most pianists who play Chopin in a 700-seat recital hall would probably sound better on something like the Model C, which is more balanced, they use the nine-footer.” For lack of demand, Steinway stopped manufacturing the Model C in America years ago, restricting production of the instrument to its factory in Germany.

That alone would have complicated Farley’s efforts to make the Voice of God speak. But Farley didn’t just want to get the right parts for the instrument–he wanted to get the best parts. So, while most restorers might use generic supply-house tuning pins (used to tighten the piano strings), Farley hunted down the same pins Steinway used 101 years ago–“at four times the cost,” he points out. “We tried three different types of hammers before we found the best ones. The treble wire is more expensive than most factories would use today. It’s from Germany, and we believe it’s the finest in the world. It has a lot of elasticity, which provides a lot of high harmonics”–and a correspondingly richer, more complex sound.

But the most striking and extravagant touch concerns the Voice’s iron-wound bass strings, as opposed to the copper-wound strings used today. As Farley explains, “The iron-wound strings act as a harmonic filter. Because of that, they don’t resonate so much with the overtones produced by the upper strings. When piano makers switched to copper early this century, it was mostly for commercial reasons: the copper strings just looked to the layman more spectacular and beautiful, and that increased sales. The copper has maybe a bit more brilliance in the bass. But with iron-wound strings the artist can make more use of the bass notes, and of the pedaling that the composers stipulated.” To assure the historicity of his choice, Farley sent the Voice of God’s original bass strings to England to have them analyzed for iron content and precisely re-created.

Those bass strings will come in handy when the Voice of God encounters Dave McKenna. As Farley proudly points out, “It’s not a real commercial-sounding instrument; it produces the kind of dirty bass sound that Dave likes.” Um, dirty bass, Tim? “That was how an English guy from Steinway described it–‘Ours is a kind of dirty sound,’ he said.” Apparently the Brit meant “earthy,” but up at Farley’s House of Music, “dirty” has stuck.

Farley himself first encountered McKenna’s music in the early 80s and instantly fell in love with it; a few years ago he got to present McKenna in performance. That’s also when Farley met Scott MacKenzie, the Chicagoan and amateur impresario responsible for McKenna’s visits here. MacKenzie does what he does for one reason: he wants to make the midwest more aware of his favorite piano player. So he lines up a Chicago date each year, then calls around the area to see what other presenters are interested. This year, when MacKenzie called the House of Music, Tim Farley decided the time had come to finish restoring the Voice of God. “This was our goal,” he says–“to finish the work in time for Dave to play it.”

Farley will transport the Voice of God to Chicago for tonight’s concert, then back up to Madison, where McKenna will perform Saturday and Sunday. Scott MacKenzie, who will drive McKenna up to Wisconsin for the weekend gigs, marvels aloud at Farley’s dedication. “I thought I was a nut on McKenna,” he says. “Now I’m taking lessons from Tim.”

Dave McKenna and the Voice of God perform tonight at 8 in the LaSalle Ballroom of the Holiday Inn Chicago City Centre, 300 E. Ohio; the $15 tickets are available only at the door. McKenna will also play Saturday at 8 at Farley’s House of Music, 157 E. Wilson, and Sunday at 8 at the Edgewater Hotel, Wisconsin Avenue at Lake Mendota, both in Madison. Tickets to the Madison shows are also $15; call 608-255-6353 to reserve them.