Yet the differences are substantial, even irreconcilable. Mr. Schnittke has placed himself in the main line of German tradition; he has passed the ultimate hurdle of Germanic art by writing his own "Faust." At the same time his work is marked by devastating pessimism, a certainty that classical traditions have come to an end. Ms. Gubaidulina, by contrast, has sought freedom and escape; she has avoided standard genres, used non-Western instruments, inclined toward improvisation, and cultivated a complex form of religious mysticism.
So it seems appropriate that recent performances of these composers' works have taken place in very different surroundings. Mr. Schnittke's "Historia von D. Johann Fausten," perhaps the most important premiere of the last decade, appeared late last month beneath the modern hulk of the Hamburg State Opera. This week, Ms. Gubaidulina's music floats out over the quiet, otherworldly Austrian village of Lockenhaus, the home of Gidon Kremer's engagingly informal Kremerata Musica Festival.
The increasing bitterness of Mr. Schnittke's music perhaps can be explained by his deteriorating physical situation. In recent years he has suffered a series of severe strokes; he has yet to recover from the last, in June 1994. Yet his productivity up to that time had been phenomenal. "Faust" was one of two operas that received almost simultaneous premieres: The other was "Gesualdo," at the Vienna State Opera. Mr. Schnittke also completed his Sixth, Seventh and Eighth Symphonies, a ballet based on Ibsen's "Peer Gynt," a Triple Concerto and various chamber, vocal and choral works.
Whether this recent music is at the same level as his exuberantly eclectic, all-mocking earlier scores remains to be seen. The Eighth Symphony and "Peer Gynt" occupy a spacious Mahlerian canvas; the other symphonies, heard last year in New York City, are almost intolerably fragmented and forlorn. "Faust," based not on Goethe but on the anonymous original published in 1587, at first bears all the hallmarks of the composer's desolate style: Grinding pedal points, fractured triads, creeping solos for the like of double bass, contrabassoon and tuba, pained silences in the rest of the orchestra, a few abrupt cluster chords.
But Mr. Schnittke has been preparing this "Faust" for many years, and the final act makes use of the score written in 1983, before his change of course and decline in health. This is the "Faust Cantata," a tour de force narration of Faust's descent into hell. In an inspired anachronism, Mr. Schnittke casts the climax in the form of a diabolically melodious tango, with a contralto croaking in Brechtian style into a microphone and an electric guitar thundering underneath. He then retreats to chilling medievalisms for the admonitory epilogue. No Goethean redemption here: Faust's is a lurid life that ends badly.
Is this Mr. Schnittke's long-awaited masterpiece? It was difficult to tell in Hamburg. John Dew's production unleashed spectacular demonic imagery, mixing Dürer, Leonardo, Cy Twombly and Ken Russell. (In one scene Mephistopheles plays a pink piano.) The staging had enormous cinematographic and choreographic energy, but it distractingly one-upped Mr. Schnittke's densely allusive score. The conductor, Gerd Albrecht, chose to make a number of cuts, telescoping three acts into two parts and dissolving an extended ballet interlude into intermittent fragments.
The result, while grimly brilliant as pure theater, was not quite what Mr. Schnittke seemed to have in mind. One hopes the composer recovers to put his opera in final form; even if he does not, the torso heard in Hamburg stands as a major event in itself. Act III achieves a hurtling dramatic momentum that has not been seen in German opera since the death of Berg.
Mr. Schnittke did not attend the "Faust" premiere, an event heavily patronized by elements of high culture and big business. The contrast could not be more complete to the dressed-down concerts here in Lockenhaus, with its programs invented day by day. Ms. Gubaidulina has been very much in evidence; on Monday night she energetically whirled among an exotic array of Asian Russian folk instruments, leading an extraordinary performance by the improvisation group Astraea.
Alongside two like-minded colleagues, the composer Viktor Suslin and his son Alexander, Ms. Gubaidulina demonstrated that a carefully controlled improvisation can have an electricity unmatched by printed music. The two pieces on Monday moved from an anarchic free-jazz-like textures to steady ostinato beats or widely spaced lyric solos. They seemed no less fully argued than the notated works heard later in the evening, Ms. Gubaidulina's savagely concise 10 Preludes for cello and Mr. Suslin's softly chiming "Mitternachtsmusik."
In her way, Ms. Gubaidulina is no less eclectic than Mr. Schnittke. At passing moments, her music alludes to Russian Orthodox chant, Russian and Tatar folk tradition, Bach, even Webern. But the citations are all part of a viscerally evolving fabric in which recognition of sources is secondary. She refuses the intellectualism common to 20th-century composers; her work is wholly devoted to fullness of sound and richness of story. Its deep intelligence becomes apparent only on later hearings.
This is not to give one composer precedence over the other. Although Mr. Schnittke offers no way out, his journey into the depths of musical history is immensely enthralling. His accomplishment in "Faust" is singular; no composer before him has come so close to the story's primal terror. But Ms. Gubaidulina's music offers hope, which is something no less rare and more precious.