American jazz meets Iraqi maqam music: This composer is a master, and blender, of both

"I like being in the situation where I don't know if something is going to work," said Amir ElSaffar with a sheepish smile. "It is a special moment for me. And it is part of my diabolical side that I put others through this process."

ElSaffar will have another "special moment" Saturday night at the Walker Art Center. He will put 16 other top-notch musicians from around the globe — his Rivers of Sound Large Ensemble — through a tricky, difficult interplay involving brass, woodwinds, strings, keyboards and a wide range of percussion.

Rivers of Sound blends contemporary American jazz with the centuries-old music known as maqam, an endangered style once predominant throughout the Middle East and North Africa (its influence extended as far as southern Italy and parts of China). The fusion of these two distinct styles was essentially invented by ElSaffar, a 39-year old Chicago native with an Iraqi father and American mother.

The Walker performance won't be as daunting as Rivers of Sound's debut at Lincoln Center in New York in April 2015, where the band performed an 80-minute suite called "Not Two." Nor will it be as intense as recording the suite in a marathon 14-hour session the very next day.

But the number of times the group has been onstage remains in the single digits, owing to the cost and scheduling logistics of bringing together so many in-demand musicians from throughout the Middle East, Africa, Europe and the United States. (Ironically, the only original member who won't be present in Minneapolis is Golden Valley native Craig Taborn, replaced on piano by Cuban-born Aruan Ortiz.)

"It's an ensemble of virtuosos and the perfect kind of project for us," said Philip Bither, the Walker's senior curator of performing arts. "For me personally, I feel like the most exciting development in jazz over the last 10 or 20 years is its melding of world traditions, how ancient ways of music can affect a great American art form like jazz."

ElSaffar grew up singing in a Lutheran choir. He was in eighth grade when the Gulf War broke out, and soon found himself visiting his father's relatives in Iraq for the first time.

He embraced his mother's love of Bach and studied classical music as a trumpet player in college before enmeshing himself in Chicago's fertile jazz and blues scenes. He moved to New York around the turn of the century and was quickly established on the New York jazz scene, striking up a productive kinship with pianist Vijay Iyer and saxophonist Rudresh Mahanthappa. It so happened that the night before the attacks on Sept. 11, 2001, he performed with Arabic musicians for the first time. The experience left him feeling ecstatic.

Fearing world events would cut off access to this part of his heritage, he spent much of the next few years in Iraq and other parts of the Middle East, pursuing the region's masters of maqam. He learned to speak Arabic, vocalize with the appropriate inflections and intonations, and perform on the highly resonant stringed santur.

He considers it serendipitous that this period dovetailed with a series of classes and then concerts with a big band led by iconic avant-garde jazz pianist Cecil Taylor back in the States.

ElSaffar was busy traveling around Iraq and Egypt in 2002 when he received an invitation via e-mail to perform with Taylor at the Knitting Factory in New York City. "So I flew back and did two mind-blowing nights with about 30 people," said ElSaffar. The band was later pared down to 18 for a residency in Macedonia. "We did three weeks with rehearsals and those were the seminal meetings that gave me an extended understanding of the connection between maqam and jazz."

For reasons of both economics and simplicity, ElSaffar next formed a small sextet, called Two Rivers Ensemble, to work on blending the two genres. They have recorded three critically acclaimed albums and form the core of Rivers of Sound Large Ensemble, providing ElSaffar with experienced hands, including the rhythm section of drummer Nasheet Waits and bassist Carlo DeRosa. In addition to saxophonist Ole Mathisen, the smaller ensemble (Two Rivers) also contains the santur, oud and buzuk, all stringed instruments common to maqam.

Maqam is a microtonal music, meaning its intervals are much smaller than in Western music. That makes for a challenge when it comes to harmonizing with jazz, especially in a large ensemble such as Rivers of Sound. Traditional Western harmony instruments such as the vibraphone, guitar and piano must be retuned to synchronize with traditional maqam instruments.

ElSaffar also creates broad rhythmic cycles that deploy Middle Eastern percussion such as the double-sided mridangam, frame drums and dumbek along with the American-style drum kit.

The result is a richly textured work of varying currents and accents. Sinuous rhythms like Indian ragas mix with moments of glossy tranquillity and gradually escalating silos of group intensity — goaded by solo improvisations — that are thrilling to hear.

"There is a lot going on," said Mathisen, a member of both Two Rivers and Rivers of Sound Large Ensemble. "In Rivers of Sound we have to make sure the saxophones don't overwhelm the other horns, and then make sure the horns don't drown out the strings. A third part is these interlocking, ululating patterns that are 30 beats or 20 beats and you have to follow the drums and the guitar."

The highest ideal in maqam music is to reach a state of "tarab" or selfless musical ecstasy. "Anybody who has worked with Amir knows about this," said Rajna Swaminathan, who plays mridangam. "In the beginning we were just trying to be on the same page, but as we play each time, we are keyed into [all] the different aspects of the musical experience. The way he has composed the music, the transcendent sense of community is there for us in the structure — whether it is transcendent in the musical sense or the spiritual sense depends upon the musician."

Whether or not tarab can be achieved on any given performance is, of course, unknown — just the way ElSaffar likes it. A special moment waiting to be inhabited.

Britt Robson is a Twin Cities-based writer. On Twitter: @brittrobson