Before this long ordeal, music had come easily to him. The son of a heavy-machinery operator who left when Arvo was 2, Pärt moved into a more cultured milieu once his mother remarried a few years later. His stepfather was a commercial sign painter; in the family house were a concert piano and a stash of scores. The piano was lacking many keys in the middle register — “like a 5-year-old child with teeth missing,” Pärt told me. But even with this dilapidated instrument, he demonstrated his talent. His musical ability propelled him to a position as a drummer when he was drafted into the Soviet Army, and later to a place at the musical academy in Tallinn. There he became known as someone to watch — which, in the Soviet Union, was a mixed blessing.

As a young man, Pärt composed music that was exuberantly and aggressively modern. In 1962, his first orchestral piece, “Nekrolog,” was also the first Estonian 12-tone music to be performed; as Pärt’s biographer Paul Hillier recounts, it stirred great controversy, earning a specific denunciation in Moscow as “avant-garde bourgeois music” by the formidable musical arbiter Tikhon Khrennikov, secretary of the Union of Soviet Composers. Serial music was just one of the styles that Pärt was exploring. In numerous works of musical collage, a compositional approach that was popular with Shostakovich and other Soviet composers, he incorporated passages of shrill dissonance. Some pieces were nonsensically Dadaesque: in his Second Symphony, the musicians at certain points are instructed to crinkle pieces of brown wrapping paper or to squeak children’s toys.

Other works were more politically provocative. In 1968, he caused an uproar when his choral piece “Credo” was premiered. This time, the Latin text — it proclaims, “I believe in Jesus Christ” — is what outraged the devoutly atheistic authorities. Neeme Jarvi, who conducted the sole Soviet performance, told me: “The law was that you first had to show the score to the composers’ union. I didn’t. I thought they wouldn’t let us. The Estonian Philharmonic organization said, ‘Let’s do it.’ Next morning it was a big scandal in the Politburo of Estonia. Then the pressure starts. Some people were sacked from the Philharmonic organization.” He says that he retained his position because no one was available to replace him, but that the scandal dried up Pärt’s official commissions, forcing him to rely on writing film scores to earn a living.

In retrospect, what is most important about “Credo” is that in it, Pärt described in musical terms the crisis that was afflicting him. The composition juxtaposes a lovely harmonic progression from Bach’s Prelude in C with violently discordant music. “I wanted to put together the two worlds of love and hate,” he explained. “I knew what kind of music I would write for hate, and I did it. But for love, I was not able to do it.” That was what drew him to the idea of borrowing Bach’s theme and incorporating it into a collage. Like a tone poem, “Credo” dramatizes a story, in this case a scene from the New Testament. As Pärt explained, “It was my deep conviction that the words of Christ — ‘You have heard an eye for an eye, a tooth for a tooth, but I say to you, Do not resist evil, go with love to your enemies’ — this was a theological musical form. Love destroyed the hate. Not destroyed: the hate collapsed itself when it met the love. A convulsion.” So it is in “Credo.” Early on, the piece introduces the Bach quotation, the notes evolve into a sequence that is transformed following the rules of 12-tone music and then erupts into dissonance and clashing before subsiding once again into a gentle reprise of the Prelude.

After “Credo,” Pärt stopped composing. He no longer believed in the musical forms he had depended on. “I think if the human has conflict in his soul and with everything, then this system of 12-tone music is exactly good for this,” he told me. “But if you have no more conflict with people, with the world, with God, then it is not necessary. You have no need to have a Browning in your pocket, or a dagger.” One day, around that time, he thinks perhaps it was in a bookstore, he heard a snippet of Gregorian chant playing on a radio; it was like a window opening onto another world. “In one moment it was clear how much deeper and more pure is this world,” he continued. “Everyone has many antennae, and they catch what we cannot even register in our minds. But the feeling is clear.” In his obsessively thorough way, he began to study monody — the single line of Gregorian plainsong — and the birth of Western polyphony in medieval and early Renaissance music. He filled his notebooks with ancient melodies.

I asked if his attraction to religious music drew him into the church, but that was a distinction he didn’t recognize. “There is no border that divided,” he said. “Religion and life — it is all the same.” He was reading early Christian writings while he was immersing himself in musical study. “The old music, when it was written, the focus of this music was the Holy Scripture for composers for centuries,” he said. “It was the reality for every artist. Through one, you can understand the other. Otherwise, you are like some teachers in the Soviet Union who say, ‘Bach was a great composer but he had a defect; he was religious.’ It means this teacher cannot understand the music of Bach.”