Sofia Gubaidulina, a Soviet-born composer whose experiments with tone and form left her blacklisted by authorities before she became one of the most influential contemporary musical innovators with works that explored spirituality and mysticism, died March 13 at her home in Appen, Germany. She was 93.

The death was announced by her London-based musical publisher, Boosey & Hawkes. Ms. Gubaidulina had battled cancer.

Mr. Gubaidulina’s more than 100 compositions, including chamber pieces, solos and cantatas, often sought to express the power of faith — including her own spiritual journey — with musical flourishes such as soaring cellos and throbbing percussion punctuated, at times, by intimate moments of silence, meditative lulls or discordant contretemps.

She described her free-roaming style as a reflection of human struggles to comprehend the divine. “Music,” she once said, “connects the finite with the infinite.”

As a student in the Soviet cultural arts system, her early inspiration came from the Western canon of Bach, Mozart and others. Her other references came from the ethnic and religious mix of her native Tatar region on Russia’s western steppes as well as within her family: the Muslim heritage of her father and the Russian Orthodox lineage of her mother.

Ms. Gubaidulina (pronounced goo-by-DOO-lee-na) ranged widely in her instrumentation, adding elements such as the 13-stringed Japanese koto, bongos and electronic mixes. A recurring motif was the undulating rhythms of the bayan, a traditional Russian button accordion, that evoked memories of her youth in works such as “De profundis” (1978) and “Seven Words” (1982).

In the 1968 cantata “Night in Memphis,” a male chorus, piano and string ensemble interpret ancient Egyptian texts. Another vocal work, “Rubayat” (1969), based on Persian ghazals and writings of Omar Khayyám, Hafez and others, included portions with shouting and laughter.

“The art of music, like any other art form, is affected by an existential feeling,” Ms. Gubaidulina once said. “Why?”

The evocative imagery of Russian Orthodox icons first stirred her interest in religion as a child, she recalled. “Suddenly the child’s imagination turned to the sky,” she said in a 1990 documentary on BBC. “I sat in that bare yard, with a rubbish dump in the middle, nothing else for a child’s ideas. I looked up at the sky, and I began to live up there.”

She knew, however, that any overt expressions of faith could derail her state-guided musical studies as she moved from youth classes in Kazan, the capital of the Tatar autonomous republic, to the prestigious Moscow Conservatory in 1954.

Nearly all Western contemporary music was banned by Soviet officials, but the students used underground networks to obtain scores by composers including the American experimental master John Cage. “We knew everything on the sly,” she recalled.

For Ms. Gubaidulina, the freedom of Cage’s works brought back memories of how she would try to coax different sounds by putting metal screws and wooden blocks on the strings of the old Schlosser piano in her childhood home.

Her interest in modernism led to a renegade reputation at the conservatory despite support from renowned Soviet composer Dmitri Shostakovich, who privately encouraged her musical path. She received state commissions in the late 1960s to create scores for films including the animated TV series “The Adventures of Mowgli,” based on Rudyard Kipling’s “The Jungle Book.”

She co-founded a folk ensemble, Astreja, in the mid-1970s. The state soon put brakes on her career. She was blacklisted in 1979 as one of the “Khrennikov’s Seven,” a reference to a group of composers denounced by Tikhon Khrennikov, the head of the Soviet Composers’ Union. They were accused of writing “noisy mud … unconnected with real life.”

Her West German music publisher managed to smuggle out one of her scores, the violin concerto “Offertorium,” which premiered at a festival in Austria in 1981. Many Americans were introduced to her work in 1985 when “Offertorium” was performed by the New York Philharmonic along with Latvian soloist Gidon Kremer, who had been a key champion of her work in Europe.

To Western audiences, she and other noted Soviet composers restricted by the state, including Alfred Schnittke and Edison Denisov, became symbols of Moscow’s cultural chokehold. Ms. Gubaidulina, meanwhile, broadened her experimentation to include compositions based on mathematical progressions such as the Fibonacci series, which grows by cumulative addition (1+ 2 = 3, 2 + 3 = 5 and so on.)

And she again turned to poetry — this time T.S. Eliot’s “Four Quartets” — for a vocal composition, “Hommage à T.S. Eliot.” Following a 1987 performance, New York Times reviewer John Rockwell called the piece “music of heart, intellect and passion,” adding that it was “full of a concentrated intensity that reinforces the religious visions of the poetry.” At other times, reviewers suggested her longer works could become ponderous and overly complicated.

During political and social openings in the Soviet Union in the late 1980s, Ms. Gubaidulina’s works reemerged at home. For the Moscow State Symphony, she wrote a 12-movement symphony “Stimmen … verstummen,” or “Voices … silenced,” that included one section in which the orchestra remains still and only the conductor’s baton stays in motion.

Soon after the collapse of the Soviet Union in 1991, Ms. Gubaidulina moved to West Germany and began work on some of her most ambitious scores. “The Canticle of the Sun” (1997), inspired by writings of St. Francis, includes a chamber chorus, cello, piano and percussion. Her “Passion and Resurrection of Jesus Christ according to St John,” completed in 2002, comprises two oratorios for orchestra based on biblical texts.

Ms. Gubaidulina often described her life’s work as an attempt to restore connections to a world beyond this one. “There is no more serious task for music than this,” she said.

Sofia Asgatovna Gubaidulina was born in Chistopol, near the confluence of the Kama and Volga rivers, on Oct. 24, 1931. Her father was a land engineer, and her mother was a teacher.

As a child, she was first noticed by Soviet cultural gatekeepers when she performed freestyle dances to the accompaniment of a traveling bayan player. She was given a spot in a school for musically gifted children.

Her most recent works include the 2018 oratorio “Über Liebe und Hass” (About Love and Hate) and the orchestral symphony “Der Zorn Gottes” (God’s Wrath), completed in 2020.

Ms. Gubaidulina’s marriages, to poet Mark Liando and dissident publisher Nikolai Bokov, ended in divorce. A daughter from her first marriage, Nadezhda, died in 2004. Her husband, conductor Pyotr Meshchaninov, died in 2006. Survivors include two grandchildren.

Ms. Gubaidulina often spoke about various instruments as if they held metaphysical powers, once calling the sound vibrations from drums as existing “at the boundary between the conscious and the subconscious.”

She saved some of her most lyric descriptions for her lifelong companion, the bayan. “Do you know why I love this monster so much?” she said. “Because it breathes.”