MJQ and Kronos: Two Sides of Same Mirror : Music: Members of both groups call their joint West Coast tour a natural idea. They play UCLA tonight.

It seems an unlikely pairing: the jazz combo that, in the ‘50s, began donning tuxedos to bring music into the concert halls, and the string quartet that, sans formal wear, went beyond the usual classical repertoire to perform jazz, ethnic and experimental compositions, even rock ‘n’ roll.

But members of the Modern Jazz Quartet and the 12-year-old Kronos Quartet don’t see it that way. In fact, according to John Lewis, music director of the MJQ, and David Harrington, violinist and spokesman for Kronos, rehearsing together last week was much like looking into a mirror, a mirror that can see across the years.

“They kind of remind me of ourselves when we began nearly 40 years ago,” said Lewis last week during a phone conversation from his home in New York.

Added Harrington from San Francisco, “Each of us in Kronos feels we’ve been watching these four older masters and thinking that, in a way, we’re almost seeing ourselves in 30 years time or so.”

The MJQ (pianist Lewis, vibraphonist Milt Jackson, bassist Percy Heath and drummer Connie Kay) and Kronos (violinists Harrington and John Sherba, violist Hank Dutt and cellist Joan Jeanrenaud) began a joint West Coast tour Friday in Eugene, Ore. They play tonight at UCLA’s Royce Hall and Sunday at the Orange County Performing Arts Center in Costa Mesa. Each of the quartets will play individual programs, then combine forces on three John Lewis compositions.

Both men say the concept was a natural. “I first heard the Modern Jazz Quartet when I was 15 or 16 years old and, since then, I’ve admired the beauty of their ensemble playing and the feeling they project,” Harrington explained. “(The idea of playing together) actually developed very organically, evolving from them being a quartet that’s been together for nearly 40 years and Kronos desiring to have that kind of longevity.”

“I don’t know who first proposed it,” said Lewis. “It just happened. It’s a natural idea.”

Their relationship actually goes back almost 10 years to the 1981 Monterey Jazz Festival, when Lewis composed a piece for the string quartet and performed it with them. “After that,” Harrington continued, “we started running into each other.”

“I’ve been following their career since that time at Monterey,” Lewis said. “When we first met, it was the beginning of their career and the direction they have since developed. I have great admiration and affection for them.”

Kronos has always had an ear for jazz. The group has collaborated with drummer Max Roach and, more recently, saxophonist Steve Lacy, with whom they’ll tour Europe this summer. Their recorded works include an album of Thelonious Monk compositions with bassist Ron Carter, and one of the music of Bill Evans with guitarist Jim Hall and bassist Eddie Gomez.

The MJQ has long had a reputation as an ensemble willing to transcend musical categories. Their album “Third Stream,” released on the Atlantic label in 1960, used as its title the term coined in the late ‘50s by composer, conductor and critic Gunther Schuller to describe the jazz/classical music then being written by Lewis and others. Two of the recording’s pieces involved the Beaux Arts String Quartet, including Lewis’ “Sketch,” a piece that Kronos and the MJQ rehearsed last week in New York.

Both groups will open with individual programs that neatly capsulize their directions. Kronos will perform compositions written for them by new-music composer John Zorn, Hungary’s Istvan Marta and Ugandan Justinian Tamusuza, as well as an arrangement of Jimi Hendrix’s “Red House.” The MJQ will present a selection of numbers from George Gershwin’s “Porgy and Bess” and a pair of Duke Ellington compositions.

Among the pieces the two quartets have scheduled to perform together is Lewis’ “A Day in Dubrovnik” in three movements, which can be heard on “Three Windows,” the MJQ’s 1987 album with the New York Chamber Symphony. Gary Giddins, author and jazz critic for New York’s Village Voice, has said that the piece “is as close to authentic romance as late 20th-Century music dares to get.”

Harrington is looking forward to the tour. “The way Connie Kay lays back on the beat, the way Percy Heath fits in with us, it’s very civilized, gentlemanly. Their ‘quartetness’ is something very special. They’ve found the best way for them to make music and to put the pieces together. The way they relate to each other is something we admire very much.”