Ensemble Signal. (Stephanie Berger/Stephanie Berger)
Classical music critic

Who are the most important living composers? Philip Glass and Steve Reich are often lumped together in people's minds as the Hertz and Avis of "minimalism," the maverick musical style that emerged in the 1970s whose hallmark was repeating patterns of notes. But where Glass is a wildly prolific jack-of-all-trades, writing everything from film scores to piano etudes, Reich has a kind of monkish single-mindedness, pursuing his ideas with tenacious focus, so that throughout his oeuvre there is a clear through line leading from one piece to another.

Reich is 81 now, and Wednesday the Library of Congress opened its season with a sensational concert of his music by Ensemble Signal, co-produced by Washington Performing Arts and featuring the East Coast premiere of a work commissioned by a consortium that included both institutions, a piece called "Runner" (2016).

The first striking thing about the concert was that Reich was there. The evening opened with him and the ensemble's conductor, Brad Lubman, taking the stage for a performance of his seminal 1972 piece "Clapping Music," written for two pairs of hands. Reich looks the same as ever — slightly more bowlegged, and slightly grayer, but no less austere, sporting his signature baseball cap and offering, without fanfare, a workmanlike performance of a piece that was written to cut down on equipment. Clapping into microphones, the two performers spin out the same rhythms in slightly different ways, moving in and out of sync with each other — a device that remained a Reich signature for the next four-plus decades.

The next striking thing was that all of the other music on the program was so new. The oldest piece, apart from "Clapping Music," was the Double Sextet, which had its premiere in 2008 in Richmond and for which Reich was awarded the Pulitzer Prize in 2009. Also on the program, in addition to "Runner," were the Quartet from 2013 (for two pianos and two marimbas, cornerstones of Reich's vocabulary); "Pulse," from 2015; and, as an encore, the final movement of "Radio Rewrite," Reich's take on Radiohead (Et tu, Reich?), which had its premiere in 2013. Rather than a career retrospective, the evening was a celebration of an active composer who appears to be exploring his more melodic, more richly instrumentally textured side — a "late style" that at least since the Double Sextet has been coming steadily into focus.

Ensemble Signal has been focusing on Reich recently, with two first-rate recordings of some of his major works, including his 1976 "Music for 18 Musicians," arguably his most influential. For younger players, Reich's music is part of the canon now, which means they approach it like any other music — and play it, arguably, more musically, with more beauty, than earlier performers who focused mainly on its newness. This approach only underlined Reich's intensifying concerns with the textural intricacy and melodiousness of acoustic instruments. The opening measures of "Pulse," indeed, evoked the flavor of Copland's "Appalachian Spring."

And while Reich has said he is not much interested in writing again for orchestra, the program showed him making much of a large chamber ensemble — especially because this ensemble plays the Double Sextet not as six instrumentalists playing with a recording of themselves, as it was performed at the 2008 premiere, but with 12 live players. "Runner," the night's biggest work, is scored for 19 musicians, making for a crowded stage, with two of each instrument except the lone double bass. Reich's scores tend to be borne on the kind of propulsive rhythms manifest in "Clapping Music," and pianists David Friend and Oliver Hagen were nearly lifted from their seats by the intensity of their insistent beats, but the composer keeps holding up pieces of melody in other instruments, as if to invoke a sense of wonder at their ability to be beautiful. Reich is an old master in today's music world, and this newest work showed again that he fully deserves the title.

The program will be performed at Carnegie Hall on Nov. 2.