In 1952 John Cage made musical history when he programmed 4 minutes and 33 seconds of silence into a concert. The now famous piece is just one example of the composer’s avant-garde approach to classical music.

Spoleto resident conductor John Kennedy programmed Sunday’s Orchestra Uncaged concert to celebrate the centenary of Cage’s birth.

When looking for a composer to accompany the late eccentric, he wanted someone as far removed from the classical mainstream as Cage. He found that someone in Radiohead guitarist Jonny Greenwood.

“It’s not easy to pair something with Cage,” Kennedy said. “I wanted a young composer who embodies his spirit as an outsider. Jonny Greenwood immediately came to mind.”

Orchestra Uncaged features music by both groundbreaking artists: Greenwood’s “Doghouse” and “48 Responses to Polymorphia,” and the U.S. debut of Cage’s orchestral trilogy, “Twenty-Six,” “Twenty-Eight,” and “Twenty-Nine.”

“Cage was a pioneer,” Kennedy said. “He was one of the first composers outside of mainstream classical music to still have a deep influence on it.”

Cage approached classical music from a somewhat radical position. Sunday’s trilogy, for example, uses a method called time bracketing, which replaces the conductor with stopwatches. The stopwatches will synchronize the performers while Kennedy looks on from a seat in the audience.

Greenwood trained as a violist in his youth and studied classical music (briefly) at Oxford Brookes University. Since erupting onto the alternative rock scene with Radiohead in the early 1990s, he has been patiently redefining his role as a musician.

In March, Greenwood released an album with 89-year-old Polish composer Krzysztof Penderecki, whose 1961 piece “Polymorphia” inspired Greenwood’s “48 Responses.” Prior to that, Greenwood’s most recognizable solo work was the Grammy-nominated score for the 2007 film “There Will Be Blood.”

Greenwood is best known for his work with Radiohead — a three-time Grammy winner for best alternative album and one of the most influential bands of the 21st century. Rolling Stone ranks Greenwood No. 48 on its list of 100 greatest guitarists, ahead of icons like John Lennon (No. 55) and Slash (No. 65).

Rock stardom, however, seldom translates to respect in the classical music community.

Pop artists from Deep Purple to Yes to Metallica have dabbled in the classical realm, but few have navigated its waters as successfully as Greenwood. Typically, the orchestra serves as mere background music for wailing guitars and charismatic front men. When Paul McCartney tried his hand at orchestral composition with the 1991 “Liverpool Oratorio,” critics trashed his efforts.

“Frankly, it could make you punch a hole in a pew,” wrote a critic with The Guardian regarding McCartney’s classical work. Even Entertainment Weekly called the album “only occasionally embarrassing.”

So what does Greenwood have that Sir Paul and so many others lack?

“He understands that making an orchestral composition is very different from writing a song,” Kennedy said. “And he doesn’t take composition lightly. He’s a serious student of music.”

Greenwood’s education has taken place outside the classroom. His collegiate music studies were interrupted after only three weeks when Radiohead signed a record deal. Like Cage, Greenwood approaches classical music from the fringes. Where Cage pushed the boundaries of what the genre was capable of, Greenwood has pushed the boundaries of genre itself, having spent most of his career in alternative rock.

Greenwood’s genre-blending style appeals to classical musicians and pop music fans alike.

“It’s intriguing to study Greenwood’s personal compositional style, and then observe how it’s synthesized into Radiohead,” said Kayleigh Miller, a violist playing in Sunday’s concert. “His contributions to (Radiohead) are often textural and timbral, such as the textures of ‘Arpeggi’ or the old-timey instrumentation of ‘Life in a Glass House.’ ”

Despite spending three decades working in pop music, Greenwood has found ways to weave classical music and orchestral instruments into songs he’s written for Radiohead.

His “Life In A Glass House,” from Radiohead’s album “Amnesiac,” features drawling clarinet and a horn ensemble. He strokes his electric guitar with a violin bow on Thom Yorke’s “Pyramid Song.” And his “Motion Picture Soundtrack,” the closing track on the platinum disc “Kid A,” opens with a dissonant organ, reminiscent of the clashing chords of “48 Responses.”

“The range of color and the different types of sound he uses are very sophisticated,” Kennedy said. “Because of the way he’s worked with Radiohead and the way he thinks about sound — orchestrating all the different sonic possibilities in a band — he can apply a unique approach to the acoustic orchestra.”

Chris Baker and Leah Harrison are Newhouse School graduate students.