Murray Perahia has given thousands of concerts since making his first big mark with a victory at the 1972 Leeds (England) International Piano Competition, so it might be only natural to presume that he has a well-honed take on the works he performs. In fact, the opposite is true.

Perahia, who will appear March 22 on the Symphony Center Presents Piano Series, likes to bring what he calls an improvisatory approach to his playing. He does not mean improvisation in the literal sense but a willingness to alter his interpretations of the same program from concert to concert, making subtle modifications to such elements as dynamics, pacing and phrasing.

“I have a general idea and I’ve worked out things but I leave a lot also to the inspiration of the moment,” he said. “I change things slightly, depending on how the first note goes. Something has to flow from that that might not necessarily be the way I rehearsed. I wouldn’t want to just mimic my rehearsal.”

Such an in-the-moment approach helps explain why the 67-year-old virtuoso ranks among the most esteemed pianists in the world. Acknowledging his stature and celebrating its four-decade relationship with the artist, Sony Classical released in 2012, “Murray Perahia – The First 40 Years,” a limited-edition box set of 67 CDs spanning the breadth of his career to that point. Also included were five DVDs and a 180-page book with new liner notes and archival photographs. “Sony did that,” Perahia said, “and I didn’t have much to do with that. I was very grateful. It ended up being a very nice production. And there were a lot of recordings – many more than I had anticipated.”

Perahia has performed contemporary works during his career, including a piano sonata by British composer Michael Tippett (1905-1998) that he recalls playing during one of his past Chicago concerts. But in recent years, he has returned to focusing primarily on the familiar core composers of the Classical repertoire, including J.S. Bach, Haydn, Beethoven and Chopin — works by all of whom will be featured during his Chicago program.

The pianist is fascinated by voice leading, the progression of individual parts or voices in a composition, and how it is affected by harmony and counterpoint. “That’s why my relationship with contemporary music was uneasy,” he said, “because I needed the tonal perspective in order to make sense of contrapuntal patterns and harmonic patterns. It’s gone back to that, because I want to know: Why is that B flat there and not a B natural? And what’s the point of it? Those kinds of questions have dogged me my whole life.”

Perahia, who appears regularly in Chicago, has been frequently showcased on the Symphony Center Presents Piano Series, which takes place in the 2,521-seat Orchestra Hall. It’s challenging to perform in such a large space, which was designed as the home of the Chicago Symphony Orchestra and not as an intimate space for recitals and chamber music. Because he also plays in such similarly large venues as Carnegie Hall in New York City, Barbican Hall in London and the Concertgebouw in Amsterdam, he has become used to them. “I’ve learned, how to deal with a hall that size, I think, in terms of tone color and projection and all kinds of things that would help,” he said. “It doesn’t daunt me as much as it used to.”

His March 22 program, which is organized loosely in chronological order, begins with Bach’s French Suite No. 6 in E Major, BWV 817. About 1½ years ago, he recorded the set of six suites, which were composed in 1722-25, but no release date has been set for the album. The suite will be followed by Haydn’s Sonata No. 31 in A-Flat Major — a new addition to Perahia’s repertory. “I love Haydn more and more and have been programming his works more and more,” he said.

Next will come Beethoven’s Sonata No. 26 in E-Flat Major, Op. 81a, Les adieux (1809-10). One of Perahia’s big, on-going projects, and one that further attests to his standing in the keyboard world, is serving as editor of the Henle Urtext Edition of the 32 piano sonatas that Beethoven composed from 1795 through 1822. One of the most important sets of works ever composed for the keyboard, they represent an extreme test for any player because of their technical demands, and emotional depth and range.

Perahia has been involved with the project for almost nine years, and he has edited about half of the sonatas so far. As research into Beethoven’s works continues and discoveries are made, the understanding of these works continues to evolve, necessitating revisions to previously published editions. “The edition that Henle produced needed updating,” Perahia said. “There were many things wrong with it. One of the things being that at the recapitulations, they reproduced all the same articulations that Beethoven did at the beginning, but it wasn’t necessarily what Beethoven wanted. It’s a good edition, but there are a lot of mistakes, and mistakes appear when anybody does an edition.”

In editing this new published set of Beethoven’s sonatas, Perahia views his goal as coming as close as possible to how the composer envisioned each work. To do that, he is studying manuscripts and previous editions, as well as compositional sketches, something he said that earlier editions largely ignored. “Beethoven did a lot of sketching, and if we study these, we can know sometimes his intention,” he said.

According to Perahia, a hand-written copy of the Sonata No. 26 owned by its dedicatee, Archduke Rudolph of Austria, was recently uncovered, and there are many differences between this version and the first published edition of the piece. “This will be the first edition that uses that source, and it’s an important source,” he said.

The challenge for Perahia is to figure out which variations between the earlier copy and the first edition were changes that Beethoven intended and which were mistakes that were made in publication. “That’s very difficult to know,” he said. “You just use your best judgment, but you check the sketches, and you see what his development was in the course of the piece and you try to make an educated guess.”

The one slightly less familiar composer on Perahia’s program is César Franck (1822-1890), who wrote in the French Romantic style. Perahia will play his Prélude, Choral et Fugue, Op. 21 (1884). “It’s not completely new [to me] in that I played it many years ago,” he said. “But I was never satisfied with my performance, and I didn’t feel I quite understood the piece. So that’s a somewhat different idiom for me than, let’s say, Classical-era composers.”

Because he felt like that piece wasn’t “conclusive” enough, Perahia has chosen to end the program with a work in the same key, Chopin’s Scherzo No. 1 in B Minor, Op. 20 (1831-31).  “Unlike the Franck,” Perahia said, “which is a sort of relationship between prayer, a chorale and doubt, which is the fugue, the scherzo is demonic. It’s nothing to do with God and those questions. It remembers in the middle section a Christmas song that was sung in Poland, probably when he [Chopin] was in Poland with his family, but the main point of the piece is the feeling of exile and, the feeling of — unease is too small a word — having to readjust to leaving Poland.”

Kyle MacMillan, former classical music critic of the Denver Post, is a Chicago-based arts writer.