Driving rhythms, superhuman speeds

Great composers are musical visionaries who change how we hear the world.

The greatest composer whose work you may never have heard could be Texarkana , Ark., native Conlon Nancarrow (1912-1997) , the maker of quintessentially American music who nevertheless spent most of his life as an exile in Mexico City, having fled the persecutions of the McCarthy era. Spend enough time with his music and it just might rewire your brain.

Nancarrow's influential compositions have been called the most rhythmically complex ever written. So much so, with their multiple layers of tempos and often superhuman speeds, that the bulk of them are unplayable by mortal musicians. Beginning in 1947, Nancarrow resorted to a machine, the player piano, to realize his musical visions, painstakingly punching piano rolls by hand and sometimes taking years to complete a piece only a few minutes long. The resulting series of "Studies for Player Piano " is among the richest and most engaging bodies of work produced in the latter half of the 20th century.

Tomorrow night at the Isabella Stewart Gardner Museum, Nancarrow's music will be performed by Alarm Will Sound, the acclaimed young 20-piece new-music ensemble, as the latest installment in the museum's Composer Portraits Series, presented in collaboration with Columbia University's Miller Theatre .

Alarm Will Sound was drawn to Nancarrow for several reasons, says managing director and composer Gavin Chuck . "The first thing about Nancarrow is his uncompromising dedication to his musical ideas. You have to admire somebody who is as committed as that," says Chuck by phone from Ann Arbor, where he is an assistant professor at the University of Michigan School of Music. "And the ideas themselves are radical. Most music around that time was something you could tap your feet to. For Nancarrow's music you would need five feet."

"It's catchy. It's fun," says Alarm Will Sound's conductor, Alan Pierson , from a hotel room in Dublin. "There's so much in it that draws on early jazz, but then it's approached from this completely individualistic angle, this kind of insane rhythmic complexity. So it's music that on the one hand is simple and immediately engaging and that on the other hand is incredibly complicated and mind-bending and very challenging to play."

Alarm Will Sound revels in the challenges of playing music written for machines. Witness its astonishing 2005 album "Acoustica ," featuring the electronica pieces of Aphex Twin arranged for acoustic instruments. Chuck says that while many of Nancarrow's studies are impossible to play, "there are a bunch of them that humans can play, so coming off of our experience with the Aphex Twin project, this is a similar thing, taking something that was made for a machine and arranging it to be performed live."

The man who literally wrote the book on Nancarrow, 1995's "The Music of Conlon Nancarrow," is Kyle Gann , composer, Bard College professor, and principal new-music critic for the Village Voice from 1986 to 2005. Says Gann, from his home in Albany, N.Y., "[Nancarrow's] big contribution was experimenting with many different types of tempo contrast, and he worked that out with a thoroughness that I sometimes compare to Bach's 'The Art of the Fugue, ' in that he just very thoroughly took that one aspect of music and did most of the things you could imagine doing with it.

"I think of him as one of the great contrapuntalists ," Gann adds, "because the counterpoint in his pieces was very important, and it was rhythmic counterpoint in addition to pitch counterpoint. So he latches on to a big tradition and carries it out further. But it's not a very continuous tradition. It's really not a terribly 20th-century concern."

Yet Nancarrow's achievements have great relevance today. His use of the player piano makes him the grandfather of computer music. And his dedication to driving rhythms speaks to contemporary composers.

"In a way, he fits in better now than he did then," says Pierson. "He sort of took a vacation during the time when art-music composers were moving away from the idea of an audible pulse. But there's been a resurgence of interest in the last 20 or 30 years with writing music that does have that. So the challenge becomes how do you write music that has a pulse that you can hear but that is rhythmically interesting and fresh. Nancarrow provides one possible answer. I think that's why he's become so popular, and why people like Ligeti and [John] Adams draw on him."

Tomorrow night's program will feature arrangements of three of Nancarrow's early player-piano studies, along with several pieces the composer wrote for human musicians. Chuck explains how he adapted "Study for Player Piano No. 2" for the ensemble: "It's like a little blues tune, but it's played at four different tempos at the same time." Nancarrow's original piece put each tempo layer in a different register of the player piano to audibly separate it from the others. Chuck used orchestral colors to define each layer instead.

He also added harmonies. "Nancarrow has a tune going on in different registers and speeds but also in different keys," Chuck says. "So what I did was harmonize it in those keys [as] another way to define each layer. It's like there are three or four little bands playing at the same time."

And the musicians' groupings change, too. "When we've performed this in the past," Chuck says, "when the French horn plays with the violin, [the player] walks over to the violin so that people can see in a performance how those things are shifting. We'll try to do it in Boston, but it's a really small stage. We'll probably do a little bit of something, because it's so much a part of what we do. "

Gann expresses admiration for Alarm Will Sound. "They're a really energetic group, and the way they present themselves is very exciting," he says. "I think they're doing new music a tremendous service."

He is especially impressed by the group's ability to play Nancarrow's difficult final work "Three Movements for Chamber Orchestra" (1993) . The piece was commissioned by the New York ensemble Parnassus, which abandoned it as unplayable. Alarm Will Sound premiered the piece in 2005, and it's on the program tomorrow.

Alarm Will Sound performs at the Isabella Stewart Gardner Museum tomorrow at 7 p.m. Tickets: ($35; $30 members; $18 students) include museum admission and post-concert "Meet the Artists" reception. 617-278-5156, gardnermuseum.org.