He used the series (or twelve-tone) technique in his earliest mature compositions, such as the String Quartet of 1966, the Concerto for oboe and flute (1968), Hexagramme for piano (1971) and a violin sonata of 1973.
He got a job in 1973 working at the studio for electronic music of the Scriabin Museum. For Soviet composers of this era, the studio had much the same meaning as the RIA Electronic Music Studio in Milan, the West German Radio studio, and the ORTF Studio in Paris--it was a meeting ground for the avant-garde. Sofya Gubaidulina, Sergei Nemtin, Alfred Schnittke, and Edison Denisov were among the composers regularly working and meeting there.
Martynov helped form a rock group called Boomerang at the Scriabin Studio. For them he wrote a rock opera, St. Francis of Assisi (1978).
He was a serious ethnomusicologist, studying the music of the Caucasian nations, Tajikistan, and various ethnic groups within Russia. He also studied medieval Russian and Western music and religious musical history and musicology. This was an acceptable field of study, but it also allowed him to study theology, philosophy, and religious history as a means to express his religious feelings.
He began studying early Russian religious chant in the late 1970s, and studied Renaissance music of such composers as Machaut, Gabrieli, Isaac, Dufay, and Dunstable, publishing editions of their music. He became interested in the brand of minimalism developing in the Soviet Union in the late 1970s, a static, spiritually-inspired style without the shimmering pulse of American minimalism. The timeless quality of chants and the lack of a sense of bar lines in Renaissance polyphony entered into his version of minimalism.
At about this time, he began teaching at the Theological Institute of the Trinity-Saint Sergeius, where he has remained ever since. There was a period of consolidation in the early 1980s where he wrote music specifically tailored for use in church services, then resumed writing original music in his minimalist style.
One of his major compositions is called a nearly hour-long piece called Opus Posthumum (1993), devoted to the idea that "a man touches the truth twice. The first time is the first cry from a new born baby's lips and the last is the death rattle. Everything between is untruth to a greater or lesser extent." He also composed a much shorter Opus Prenatum and a work called Twelve Victories of King Arthur of Seven Pianos (1990).
Since the fall of the Soviet Union, he has written works that take on large Christian themes, such as Apocalypse (1991), Lamentations of Jeremiah (1992), Magnificat (1993), Stabat Mater (1994), and Requiem (1998).
He has recordings on Le Chant du Monde's imprint "Les Saisons Russes" and on the Moscow based independent label LongArms Records.