Ursula Oppens is a pianist known for deftly integrating new music and established works on her programs. Back in 1975, she was learning Beethoven’s “Diabelli” Variations for a concert and decided to commission a new piece to go with it. So she went to Frederic Rzewski (pronounced ZHEV-skee), a Westfield-born composer and pianist who, even then, was hard to pigeonhole into familiar boxes. She asked him to write the companion work, and he quickly did so.
But the piece Rzewski produced, “The People United Will Never Be Defeated!,” went well beyond Oppens’s expectations. The mammoth set of 36 variations on a popular Chilean protest song became a signature work for the maverick composer, far outstripping its role as a companion for the Beethoven. Oppens acknowledged this in a 2008 New York Times story: “Then this piece turned up,” she told an interviewer, “and I never did learn the ‘Diabelli.’ ”
“The People United” carries a daunting air of being both a powerful political statement and a technically demanding piece. Still, it appears frequently on recital programs and has become something of a repertory staple among piano music of the last half century. Stephen Drury, local new-music authority, will play it on Saturday at the Monadnock Music festival in Peterborough, N.H. He has a lengthy history with the piece, having heard Rzewski himself play it at Sanders Theatre when Drury was a Harvard undergraduate, likely at a Fromm Foundation concert in the 1970s. His initial impression?
“It was enormously long,” he deadpanned during a recent conversation from Tanglewood. “More than an hour,” the rough playing time for the piece. Rzewski gives the performer the option of improvising a cadenza before the final statement of the theme, and his own cadenza, at that performance, was so long that “you didn’t have a sense of where it left off and where the rest of the form of the piece was.”
Drury didn’t start working on the piece himself until the 1980s, when a student came to him through New England Conservatory’s prep school, wanting to spend a summer learning it. “And as we were plowing through it,” Drury says, “I started getting the bug myself, seeing how it was shaped.”
That shape, the large-scale structure of “The People United,” is essential to making the piece what it is. Given its origin, it’s often been compared to the “Diabelli” Variations; like that piece, a composer lets his imagination run wild over a simple theme, reworking it in almost unimaginable fashion. The comparison is apt, but Drury said that an even closer model is Bach’s “Goldberg” Variations. Every third variation in the Bach is a canon, where the melody is repeated by a different voice in the texture. The 30 variations thus divide logically into 10 groups of three.
Similarly, the 36 variations of “The People United” are laid out in six groups of six variations. Each of the first five variations has a distinct harmonic or rhythmic style. The sixth variation has four bars in the style of the first variation, four bars in the style of the second, and so on. “They’re not quotes, but they’re recognizable,” Drury said. The second group of variations, numbers seven through 12, has the same structure.
The last set of six begins with Variation 31, which has references to Variations 1, 7, 13, 19, and 25. The same pattern holds for the next four variations. The final variation, Number 36, “sums up the previous five, which summed up the previous hour of music,” Drury explained. The final restatement of the theme concludes the exhausting musical expanse.
This intricate structure is of more than theoretical interest, Drury added. It’s crucial to the question of whether and how “The People United” is a political artwork. It certainly seems so from Rzewski’s selection of his theme. The song “El pueblo unido jamas sera vencido!” was written in 1969 by Chilean composer Sergio Ortega. It became a rallying cry for the Chilean resistance movement when President Allende was removed in a 1973 coup and Augusto Pinochet was installed as the country’s leader.
But Rzewski has always been coy about his political leanings or those of his works. When asked once if he was a Marxist, he replied, “Harpo or Groucho or what?” He told the Globe in a 2005 interview that he had “an ordinary person’s view of politics.”
Yet, Drury said, the writing of “The People United” was “unquestionably” an act of solidarity with the Chilean people. And the formal unity of the variations, the way they link together, is the artistic expression of the song’s meaning. “That’s the title of the piece, and the meaning of the piece,” Drury said. “Quite literally: the people united.”
The musical language Rzewski used was also more straightforward than in other of his works. “I think he was concerned with making aspects of it clear, because it is a didactic piece. It has a polemic, so he wanted to make it coherent to people who weren’t specialized in avant-garde music.”
Given the piece’s size, finding something to pair with “The People United” is tricky. Drury has chosen to open his program with Chopin’s G-minor Ballade, a piece that seems to share nothing with “The People United.” Drury couldn’t really explain it himself, except to say that Rzewski, like Chopin, wrote a set of four ballads, which are also among his more popular works.
“Do they have anything to do with each other beyond that?” He paused. “Probably not, except — seems like a good program.”
David Weininger can be reached at firstname.lastname@example.org.