For many classical music lovers, the cello is a supremely soulful instrument. Its rich, deep, often mellow sound is highly expressive, whether the music is a Bach suite for unaccompanied cello or a full-bodied concerto by Dvořák or Elgar.

Norwegian cellist Truls Mørk, an internationally acclaimed musician praised for his richly passionate performances, will be soloist in Dvořák’s stirring concerto with the Chicago Symphony Orchestra in concerts April 6-8 and April 11, led by guest conductor Charles Dutoit. The program also includes Prokofiev’s Symphony No. 5 and the U.S. premiere of a long-lost piece by Igor Stravinsky, Funeral Song, a tribute to Rimsky-Korsakov, his teacher and mentor, written in 1909.

With its singing melodies and emotional depth, Dvořák’s Cello Concerto is popular with audiences and a cornerstone of the cello repertoire. But Mørk points out a surprising fact. Modern audiences may adore the cello and rank its big showcases—concertos by Dvořák, Elgar and Schumann—among their favorite pieces. But most Romantic-era composers considered it highly unsuitable for solo treatment in a concerto.

“Although there are other Romantic concertos, many of the Romantic composers didn’t really believe the cello was capable of taking part in such a big work,” said Mørk in a recent phone interview from his home in Oslo. “The cello was considered a bass instrument, very much an orchestral instrument. Most of the popular solo instruments [like the violin] are highly pitched. And the cello blended so well into the orchestra that many composers felt it wouldn’t really be able be able to cope with being [featured in] a big concerto. Tchaikovsky, for instance, didn’t want to write a concerto for cello; instead, he wrote the Rococo Variations. [Tchaikovsky’s theme and seven variations is scored for solo cello and a reduced ensemble more typical of Mozart’s era than the expanded orchestra of the late 19th century.] Dvořák was kind of the first to show that the cello was capable of taking part in a big concerto.”

In a letter written one year before he started composing the concerto in 1894, Dvořák said he was considering writing a concerto, either for violin, piano or cello. But he worried that “the cello’s lower register sounded kind of muddy and unclear, and the high register was kind of squeaky,” Mørk said. “The only part he liked was the middle.”

During a three-year residency in the United States, Dvořák heard a performance in New York of Victor Herbert’s new Cello Concerto No. 2. Best known as a composer of operettas, Herbert was also a professional cellist. “That inspired Dvořák, and showed him some good aspects of the cello.”

Now in his mid 50s, Mørk grew up in a musical family; his father was a cellist and his mother was a pianist. After piano and violin lessons failed to pique his interest, he took up the cello, relatively late, at age 11.

“I was also singing in a boys’ choir, and the connection between song and the cello was important to me,” he said. “There’s an element of the cello covering all of the human vocal register. The cello is a more expressive instrument in its nature, and it’s a big instrument. It takes more time to run over the whole register. Its songfulness and expressiveness really appealed to me.”

Mørk has appeared with the CSO only once before, in 2005 as soloist in the Schumann Cello Concerto with Jukka-Pekka Saraste conducting. He has performed at Symphony Center several times, however: with the Oslo Philharmonic in 1994, the Swedish Radio Orchestra in 2001 and in a chamber program with violinist Gil Shaham and pianist Yefim Bronfman in 2002.

This season, Mørk is artist-in-residence with Sweden’s Gothenburg Symphony, appearing with the symphony’s musicians in chamber recitals as well as orchestral concerts. Despite his love for the Romantic era, he is also committed to contemporary music, having given more than 30 world premieres. Over the years, after performing standard repertoire several times with an individual orchestra, he would urge them to commission a new work, in part to expand the cello’s relatively small repertoire.

“I see myself as a musician who wants to be almost like a tool for the composer,” Mørk said. “I don’t want to put up too many expectations for the composer or decide beforehand how I would like the music to sound. I want to be flexible and play the music as well as I possibly can in order to get more music for my instrument.”

Mørk’s interest in both contemporary and 19th century repertoire is hardly surprising, since his musical idol is the eminent Russian cellist Mstislav Rostropovich. Though his performances of the cello’s Romantic concertos were profoundly expressive, Rostropovich, who died in 2007, also worked closely with contemporary composers. His list of world premieres stretches from a sonata by Prokofiev in 1949 to important works by Shostakovich, Benjamin Britten, Witold Lutosławski and Krzysztof Penderecki.

“I remember when we got our first record player at home. I was seven or eight years old,” said Mørk. “When I was 11 or 12, we got the record, which was then quite new, with Rostropovich playing the Dvořák Cello Concerto with the Berlin Philharmonic, conducted by Herbert von Karajan. The sound of the cello, the music making, the sonority, was something that just blew me away. That opened the door for me into his style of playing.”

Expect to hear Mørk’s take on that style in his upcoming performances with the CSO. For the cellist, Dvořák’s beloved concerto is a work that never gets old.

“The piece itself is quite nostalgic,” he said. “Dvořák is looking back a bit on his own life and his connection to Czech music. To me, there’s some kind of magical quality that inspires me. I don’t know what it is, but whenever I play it, it always manages to hypnotize me into its mood and character. I feel inspired. It’s never been a problem for me to play it as often as I do.”

Wynne Delacoma, classical music critic of the Chicago Sun-Times from 1991 t0 2006, is a Chicago-based arts journalist and lecturer.