That perfection of expression and gesture ties his recital together. Beginning with a clutch of Chopin, including the heroic Third Scherzo, he moves on to Debussy and then Pierre Boulez’s hell-on-wheels Sonata No. 2. Written in 1948 when the Boulez we now know as the affable conductor emeritus of the Chicago Symphony was a 23-year-old polemic-issuing student, the violent work pulverizes the listener. Pollini knows the work well, having recorded it in 1978.

“It is amazing to see how a masterpiece of this kind, of this maturity, could be composed by such a young person,” Pollini says. Written in Boulez’s unforgivingly aggressive style from those years, the jagged, percussive work doesn’t give listeners much to hang on to in its 30 minutes. But Pollini sees a kinship with past generations of composers in the work. “The greatest composers of the 20th century, like Schoenberg, Webern, Boulez and Stockhausen, have great strains of expression in their music. In this sense, there is nothing different from the great composers of the past.” He points out that Beethoven’s last works are also hard to follow, and yet they have become more and more familiar to audiences.

Today’s listeners “should be touched by the composition immediately,” Pollini says of Boulez’s sonata. “I think they should absolutely grasp immediately the aura of this music, the greatness of this music.”

At the same time, Pollini has constructed his program in such a way that the Boulez won’t be as radical a departure from the program as it might have been otherwise. He progresses from Chopin to Boulez by way of Debussy’s final six Études, which happen to be among Debussy’s final works. They function as a hallway between Chopin’s Parisian salons and Boulez’s strictly modernist structure. “The Études by Debussy are very much looking to modernity in a very strong way,” Pollini says. “This was certainly felt very much by Boulez.”

Pollini’s quest to find those unique composers led him to the quiet works of the Italian composer Salvatore Sciarrino, born in 1947. Sciarrino composed the cadenzas to Mozart’s Concerto No. 21, and Pollini performs them on his recent CD of Mozart concertos. (He conducts the Vienna Philharmonic from the keyboard.)

“[Sciarrino] composed cadenzas for all the concertos by Mozart where a cadenza by the composer is missing,” Pollini explains. The cadenzas are in a strict Mozartean style, and there is almost nothing in them that gives away their recent composition. Every composer is unique, but sometimes the assignment is to speak in another’s language.

When I first mention that Pollini is playing a lot of Chopin and that he won the International Chopin Competition in 1960, he interjects and says, “Many years ago.” But he’s keenly interested in what happened long before he won that competition, what is happening today, and how they speak to each other.

Pollini solos Sunday 6.