Saul Williams is not someone you’d immediately expect to see sitting onstage with a string quartet playing music rooted in the abstract noise of contemporary classical music. More often, Williams has been surrounded by hip-hop beats and industrial sounds, working with people like Rick Rubin and Trent Reznor. His poetry mixes tightly intertwined literary references with the rhythms and flows of rap and African diaspora culture.

And yet there he’ll be, in the Nelson Music Room with the Mivos Quartet, in the second of two concerts that violinists Olivia De Prato and Lauren Colley, violist Victor Lowrie, and cellist Mariel Roberts will play this week. Together, these concerts make a pretty convincing case that the distance between Williams and the classical avant-garde is smaller than you might think.

The first Mivos concert, on Thursday, October 6, centers on two very different visions of what a string quartet can be at the dawn of the twenty-first century: Helmut Lachenmann’s String Quartet No. 3 “Grido” and Thomas Adès’s Arcadiana.

Lachenmann is one of the major figures of German music in the postwar twentieth century. He strips music down to its most fundamental sounds, calling on instrumentalists to use “extended techniques”scratches, pops, whooshes, clicks, and other non-pitched soundswith the same rigor and intensity as traditional tones. Consequently, his music can be dense and abstract. Grido (“cry”) was written in 2001, when the composer was in his sixties. It is, relatively speaking, one of his most accessible works. There are bits of themes, flashes of chord progressions, and even a motif or two to grab on to, though they sometimes have to fight through layers of extended techniques.

“You feel like you can understand it enough to attempt to bring a transcendent musical experience with something that’s so intensely intricate,” says Lowrie. “It’s an incredibly moving experience to play it.”

Arcadiana is, in many ways, Grido’s opposite. Adès was only twenty-three when he wrote it, and it pops with youthful energy. During seven short movements, Adès references half a dozen composers and musical approaches: Schubert and Debussy comingle with Mozart and Elgar, all imbued with Adès’s lovely twists on conventional harmony. Soaring melodies are elaborated and embellished several times over, stretching to a delicate thinness or melting away completely. And just as Adès establishes one idea, he jumps to the next. He does occasionally use some Lachenmann-esque sounds, but he uses them differently, putting their expressive qualities in the immediate foreground.

“It’s interesting to look at somebody very young, very precocious, and someone very mature and well-developed dealing with those big compositional issues in the same format, a string quartet piece that’s a hefty, serious work,” Lowrie says.

Strangely enough, the Mivos Quartet’s path to playing with Saul Williams also goes through Lachenmann. In 2012, they were in England, working with the acclaimed Arditti Quartet on that same Lachanmann quartet, among other pieces.

“Irvin Arditti mentioned that ‘there’s some piece with a rapper that we recorded that might be something you’d be interested in.’ I don’t know why he said that, but he did,” Lowrie recalls.

That piece, NGH WHT, was written by Swiss composer Thomas Kessler in 2007, who set the poem of the same name from Williams’s book The Dead Emcee Scrolls to music. The next time Williams played in New York, the members of the Mivos Quartet eagerly sought him out.

“I was completely blown away,” Lowrie says. “It was a virtuosic performance. We thought, ‘We have to perform with that guy. He’s amazing.’” After the show, the foursome sneaked backstage and introduced themselves to Williams. Two years later, they were performing NGH WHT with him at a music festival and planning further collaborations.

To write NGH WHT, Kessler analyzed a recording of Williams reciting the poem, deriving a vast palette of sounds ranging from scratches and crackles to fragments of melody and occasional beats. Because the text is so dense, he wanted the quartet to provide an extra layer of mediation or decoding, with the sounds elaborating on Williams’s words.

Kessler is roughly the same age as Lachenmann and shares many of his musical predilections. It’s not surprising, then, that NGH WHT bursts with extended techniques, melting chords, stuttering rhythms, and gritty timbres. William’s energetic recitation provides the energy that propels everything forward.

“He’s a very, very dynamic performer with a lot of energy that we feed off of,” Lowrie says.

Most of the sounds either emerge from that energy, respond to it, or reinforce it. Sometimes, the quartet mimics Williams’s rhymes, adding extra punctuation to already emphatic lines. Elsewhere, woozy chords highlight a particularly hallucinogenic passage.

To Kessler’s credit, he never actually tries to mimic hip-hop beats, even when Williams makes overt references to the sounds of hip-hop. On occasion he does settle into lopsided grooves, like when Williams slides into a Jamaican dancehall toast halfway through the piece, but he never tries to make the quartet do real boom-bap. The contrast is strangely thrilling, and the musicians relish the opportunity to expand their horizons.

“It’s fun to go through that process,” Lowrie says, “and learn more through working on the piece and talking to [Williams] about his experiences of music and what he is referencing and what his writing is all about.”

The quartet’s work with Williams has only grown over time. This concert includes a new work by Ted Hearne, who sets Williams’s poem “The Answer to the Questions That Wings Ask” on what Hearne calls “a circular but somewhat confounding chord progression.” The group will also perform arrangements of songs from some of Williams’s albums.

Each of these collaborations casts his work in a different light, suggesting new readings and hearings of his words and new twists on his sounds. They argue that rap doesn’t need beats or samples to speak, and that a string quartet can be just as powerful a vessel for hip-hop as can a sampler.

This article appeared in print with the headline “The Swiss Connection”