Last week Washington audiences heard the invincible opening of Verdi's "Otello." Nothing in the world of music is more sure of itself than the huge wall of sound from the full orchestra, reinforced by the organ, that signals the beginning of Verdi's late, great masterpiece.

This week Washington audiences will hear an equally invincible opening when Erich Leinsdorf gives the downbeat to begin the Eighth Symphony by Gustav Mahler. This time the immense sound will come from the lowest woodwinds and strings in the orchestra, but the organ, which in Verdi is restricted to a thundering trill on low C and D flat, will instead burst out, in Mahler's marking, "Full Organ," and the dynamic direction is fortissimo.

It is interesting to note the composers' tempo and expressive marks as well: Verdi calls for an opening "allegro agitato," Mahler wants his "allegro impetuoso." The purposes behind the two irresistible beginnings are as different as were the two men in their outlooks on life. Verdi was setting the scene for the violent storm that starts his opera on its unswerving path. Mahler, with that huge E flat chord, gives us about two seconds to prepare for the out-sized double chorus to cry out, "Veni, Veni Creator Spiritus." "Come, Creator Spirit, visit our souls, fill them with grace, Thou that didst create them."

Mahler was setting a famous 9th-Century hymn attributed to Hrabanus Maurus, the Archbishop of Mainz. The eight stanzas provided him with precisely the atmosphere he wanted for the first movement of a symphony about which he had a vision of a boundless universe. He wrote to his friend, Dutch conductor Willem Mengelberg, "I have just finished my Eighth -- it is the grandest thing I have done yet -- and so peculiar in content and form that it is really impossible to write anything about it. Try it imagine the whole universe beginning to ring and resound. These are no longer human voices, but planets and suns revolving."

With so vast a vision, Mahler was untroubled by any past considerations of formal design. Its roots were in the Ninth Symphony of Beethoven. There was a symphony that dared to introduce both solo voices and a chorus into the hitherto sacrosanct instrumental world of the classical symphony. It also presumed to place the scherzo immediately after the opening movement, following that with a slow movement of unprecedented luxuriance in the length of its variations. And finally, in its final movement, Beethoven's ground-breaking monument shattered anything that was still left of the classical concepts of form. Out of all this, Mahler, who had already created seven symphonies of startling originality, three of which employed voices, moved with security and self-assurance into the largest symphonic realm ever discovered.

Mahler was scrupulous about his texts. Several times he wrote to his old friend, Fritz Lohr, asking him, first, early in June of 1906, when he was eager to start work on the symphony, for a translation of the second and fourth verses of the poem. Later he wrote in exasperation, "I am beginning to think that this wretched liturgical tome from which I took the words of 'Veni creator' is not entirely reliable. Please send me an authentic text of the hymn."

With its insistent importuning of the Creator Spirit, which Mahler emphasizes by repetitions of the invocation, "Veni, veni" -- "come, come" the poem gives the composer precisely the sense of overwhelming need and the ensuing right to demand that the Spirit should indeed descend into our souls.

As he approached the lines that beseech the gift of light of our senses and love in our hearts, Mahler rose to unparalleled heights in which he called upon the entire enlarged orchestra, the double chorus, the children's chorus, and the full complement of soloists to join. His markings in the score at that point are as specific as those in certain late piano sonatas of Beethoven. To the conductor, he notes, "The triplet clinches the matter. After the triplet, a decided 'breathing pause.'" This giant moment occurs as the chrous reaches the word "accende" -- kindle. After the first syllable, "ac," is sung, there is a comma for every one of the participants. It is Mahler's way of creating an unprecedented effect and one of the great moments in the entire score.

Yet for all its tremendous choral forces, its eight soloists, and an orchestra augmented by seven added brass, organ, piano, harmonium, celeste, two harps, and added percussion, Mahler finds a place for a mandolin. A mandolin! Exactly. Because, as he said of the music, "There is no harmony -- only counterpoint." By this he meant that, with such a wealth of resources, he did not need to dwell overlong with the mightiest forces. Much of the subtlest beauty in the score occurs in the quietest pages of the second part, with its mystical scenes and visions. The entire work was completed in six weeks of that summer of 1906.

The very last lines of Goethe, which Franz Liszt used to close his Faust Symphony, also are the final lines in the Mahler: "All things transitory are but parable; here insufficiency becomes fulfillment, here the indescribable is accomplished; the ever-womanly draws us heavenward." Just as Mahler does in his accompanying music.