While working on his opera "Khovanshchina" in 1873, Modest Mussorgsky wrote, "This is a drama of the people . . . I sleep and I see them; I eat and I think of them; I drink and they haunt me." So obsessed was the composer with accurately portraying these people and a crucial page in their history (1682-89) that he turned directly to historical documents for his libretto and to Russian folk song as a source and model for melodic material, creating in the process some of his most inspired music.

The Metropolitan Opera's new production of "Khovanshchina" opened Monday evening in New York. Imaginative and innovative musical thought lies at the heart of this score, and the company's impressive solo and choral singing allowed this quality to shine through with brilliant clarity. That the Met's production failed in other ways to realize the opera's visual and dramatic potential is less a surprise than a disappointment, given the complexities of mounting the work in the first place.

The opera's central conflicts involve several factions: The nobility, represented by both the radical Ivan Khovansky and the boyar Shaklovity, who eventually murders Ivan; the Old Believers, an ultraconservative religious sect led by Dosifei; the Streltsy, an unruly military force commanded by Khovansky; and the modernizers, represented by Prince Golitsyn.

Dramatically speaking, the major characters are Dosifei and his disciple Marfa, the most complex character in the opera. Martti Talvela's rich bass voice brought both authority and tenderness to Dosifei, but Marfa's role requires more stylistic flexibility than Helga Dernesch gave it in her Met debut. Her more dramatic moments were convincing, but her voice lost its warm color in the more subtle passages, and an unfortunate pitch problem marred her climactic aria, the "Requiem of Love."

Aage Haugland acted and sang magnificently in the role of Ivan. Likewise, Allan Monk handled the part of Shaklovity with great insight, particularly in his brooding Act II aria. Wieslaw Ochman is no actor, but he sang beautifully as Golitsyn, while Andrea Velis was a perfect Scribe; soprano Natalia Rom was vocally inappropriate as Emma, however. The generally excellent singing could have had even greater impact if the Russian diction had not been so abysmal -- hardly a minor issue in Mussorgsky's vocal music.

Of the two existing versions of "Khovanshchina" (which Mussorgsky did not live to complete), the Met uses the Shostakovich orchestration, combining the five original acts into three. The staging, with the Streltsy in 19th-century garb, the Poteshny Guard in 20th-century garb, the lack of a single icon, finished lumber instead of logs, and neither dawn nor the Moscow River (to fit the Prelude's title and the entire work's subject) makes one wonder if producer August Everding gave proper weight to the historical background of the opera. Ming Cho Lee's sets are impressive but inconsistent: a monumental St. Basil's Square with a moat running through it, a Streltsy quarter that looks like a concentration camp. The Old Believers' hermitage provides a stunning setting for the final immolation scene, however.

While the orchestral playing was superb, conductor Neeme Jarvi did not communicate well with the stage, and his pacing of the work as a whole was not successful. Key dramatic moments were rushed over, while other passages lacked any sense of energy or direction. The real plaudits for ensemble work go to the chorus, which brought "Mussorgsky's people" a beauty and richness of sound that were often very moving.