William Bolcom

''I'm trying to do the same thing in music, to get back to the simple roots, to refer to the past without actually imitating it. The second movement of the Symphony, in which I use the Roethke poem, is about my personal past; the first movement is about the musical past in general, a past with which I've always been intimately involved.''

In 1982, however, Bolcom had brought to completion a three-hour setting of William Blake poems that had occupied his attention off and on for almost a quarter-century. Bolcom's gigantic ''Songs of Innocence and Experience'' is neither an opera nor an oratorio, but it is nonetheless dramatic in concept, and in its free-flowing mix of styles it is tellingly representative of what Bolcom the composer is all about. Under the baton of Dennis Russell Davies, the Blake treatment was premiered in January of 1984 at the Stuttgart Opera. A few months later it was performed at the University of Michigan, where Bolcom teaches, and in the summer of 1986 - to Krainik's delight - it was encored at Grant Park in Chicago. Bolcom's contract with the Lyric Opera would not be officially announced until 1989, a year after Bolcom won the Pulitzer Prize for his ''Twelve New Etudes'' for piano. But the Lyric's director says that as soon as she heard ''Songs of Innocence and Experience'' she knew that Bolcom was indeed her man.

''Songs of Innocence and Experience'' - which will be presented by Leonard Slatkin and the St. Louis Symphony in Powell Hall on Thursday and Friday - calls for not only chorus and orchestra but also a narrator, nine conventional vocal soloists and a rock singer. Its forces are grand and its duration long, yet it is primarily for its content that it looms so large. A significant part of that content, certainly, is found in the music. As does his new opera ''McTeague,'' Bolcom's ''Songs of Innocence and Experience'' covers a lot of stylistic territory. Some passages are blatantly tonal and tuneful, others abrasively dissonant. There are references to jazz, gospel, rock, ragtime and other popular idioms; there are also whole sections in which the musical foundation, no matter what the surface material, is based on the methods of 12-tone serialism. Together, these styles add up to what for Bolcom is a single style he calls ''the American musical vernacular.'' Listeners might be tempted to call this approach ''eclectic,'' but Bolcom finds the word not at all to his liking.

''Eclecticism,'' he said in an interview last week, ''assumes that all the categories are water-tight. In fact, all of these different kinds of music spill over into the others. They already have elements in common; they already are interpenetrating. Especially in the last few decades, composers and critics have wasted time arguing about which style - jazz or rock or classical - is the most valid. The way I see it, they're all valid, and my concern is figuring out how they all relate to one another. But it's indisputable that they do relate, and so out of them can be forged a single musical language that is as vital - and as inclusive - as the English language.

''This is what Charles Ives was trying to do, and Gershwin, and Duke Ellington. And it's what I've been trying to do for most of my career. I think I'm there. I mean, I'm using this language, and audiences seem to be understanding it. Sure, I meet with resistance, but it only comes from people with case-hardened notions of musical categories.''

Bolcom's music, then, might be self-explanatory. But the content of ''Songs of Innocence and Experience'' is as much poetic as musical. And for most Americans, the author of that poetry is a mystery.

William Blake was born in London in 1757 and died there in 1827. He was a mystic; when his brother died, he claimed to see the spirit rise from the body and pass slowly through the ceiling of the room. He was also a visual artist: Taught, he said, by the ghost of his dead brother, Blake pioneered a variety of etching techniques and used them to illustrate his poems. During his lifetime Blake was dismissed as a madman, and his poems did not gain wide circulation until late in the 19th century. Most of them are short and in the lyrical, odic vein. Probably the best known is the one that begins ''Tiger, tiger, burning bright . . . .''

In the essay that accompanies the St. Louis performances, Bolcom writes: ''William Blake is to me the most urgent of poets. What he says is as immediate as ever, but particularly to us. He came from an epoch of social change as total as ours, and we can learn from him in the time of our deepest human crisis, that of whether or not we will survive as a planet. With clear and unjudging vision, Blake saw where the human race was heading; it could be argued that (Blake's) 'Songs of Innocence and Experience' may be the clearest explanation we have of what forces have brought us to this frightening impasse.''

The statement is provocative, to say the least, and I asked Bolcom to expand on it.

''I have found solace in Blake ever since I was about 15 years old,'' Bolcom said. ''In terms of my music, he showed me the way to go. He was a very educated man, steeped in the classics, but he also knew the value of the song off the street, and he had no problem in blending the elements of all the literary styles he knew. There's more to it than that, of course. The prophetic books talk about missed opportunities in the history of the human race, about the rise of governments that could not be constructive because of some basic flaw, about the prevalence of certain attitudes that can only cause holocaust and misery. Much of this stems from our unwillingness to confront what we, as humans, really are; it's just too frightening to face. But Blake tells us what we are, and he contrasts this with what we think we are. We have innocent notions about ourselves, and sometimes we go around in a stupor because we actually believe them. Experience, on the other hand, teaches us something else.

''All around us are examples of innocence pitted against experience. Our politicians suggest that we be puritanical, yet our entire advertising industry is based on the idea of sexual titillation. On one page of a woman's magazine there is an article about dieting and on the next page is a recipe for the richest dessert you can imagine. We see pleasant little sitcoms on TV, and in the commercial breaks we see ads for anti-drug campaigns. How can you expect people to deal with these contradictions? But it is precisely contradictions of this sort that form the central theme of Blake's work. Blake, more than any other poet, dealt with the truth of human nature. And he did it in a hopeful, not a pessimistic way, because he realized that only when people face up to what they really are can they know joy.

''I think that joy, ultimately, is what my setting of Blake's poems is all about. I don't mean just happiness. I mean joy, the kind you find at the end of 'The Book of Job'; after the worst things that could possibly happen to him, Job is left with joy, because finally God tells him the truth about himself. That's it, in a nutshell. In truth there is joy.''

As appraisals of our species go, this one - by the late 18th- and early 19th-century English poet William Blake - ranks among the most bluntly honest. It comes at the very end of composer William Bolcom's 1982 setting of Blake's ''Songs of Innocence and Experience,'' after an hour of blithe optimism and then a 90-minute descent into the darkest regions of the human spirit.

Indeed, so grim are the pictures Bolcom paints after intermission that as the final song begins it is hard to remember the evening contained any bright spots at all. Instead of driving home his point with a complete and utter emotional black-out, though, Bolcom goes for the ironic twist. The last number is a reggae song; the words ought to make us feel ashamed of ourselves, yet the music - as joyous as any on the planet - makes us want to get up and dance.

Powell Hall was not at all packed for the St. Louis Symphony's performance of Bolcom's ''Songs of Innocence and Experience'' under the direction of Leonard Slatkin on Thursday night. But those in attendance must surely know that they witnessed a major musical event.

The score is remarkable for reasons aside from its uncommon length and its awesome expressive power. It represents what Bolcom calls the ''American vernacular musical language.'' It is not an ''eclectic'' piece that borrows bits of this and that to flavor an otherwise mainstream modernist style. Rather, the score blends virtually all the music with which Bolcom is familiar - with which most Americans are familiar - into a cogent whole. The idioms of the concert hall are here, but so are the idioms of the saloon, the church, the fraternity house, the grand ol' opry. Bolcom's musical contrasts are often bold, and the bleak-texted reggae segment is not his only use of irony. No matter how bold or ironic, though, the various elements never seem forced or gimmicky. On the contrary, they feel exactly right for whatever level of his multitiered message Bolcom is trying to get across at any given moment. And they all sound convincing. The gloomy song titled ''London'' was not an example of the St. Louis Symphony simply making reference to heavy metal rock music; for as long as it lasted, this was the real thing, complete with throbbing tom-toms and fiercely over-driven electric guitar.

Andre De Shields was the always-compelling rock and reggae singer. His colleagues are so numerous they can only be named here. The country singer was Lee Anna Knox, the torch singer and folk balladeer Debby Lennon, the lyric soprano Linda Hohenfeld, the dramatic soprano Mary Shearer, the coloratura Ilana Davidson, the tenors Walter Plante and John Absolom, the baritone Vernon Hartman, the boy narrator Jordan Cooper. The New York-based sextet called the Western Wind sang the madrigals; the massed voices were those of the St. Louis Symphony Chorus and the Concert Choir of the St. Louis Children's Choir.

Bolcom's ''Songs of Innocence and Experience'' is significant for its size and range and for its almost-unique synthesis of musical idioms. But it is more significant for its painfully accurate treatment of the poetry. To absorb the music is much, much easier than to contemplate Blake's assessment of what it means to be human. In this, too, there is irony.

Like the 1899 novel by Frank Norris on which it is based, Bolcom's ''McTeague'' is about greed. Gold is the dominant visual image in Yuri Kuper's set design and in Robert Altman's staging; the dynamics of corruption - of good turning to bad and then to worse - provide the basic shape of Bolcom's music. Even in the first scene, one knows how the opera will end; when the final curtain falls, the inevitable tragedy strikes unsettlingly close to home.

Although the Lyric Opera has lately been paying considerable attention to the music of living American composers, ''McTeague'' is the company's first world premiere since Krzysztof Penderecki's ''Paradise Lost'' in 1978. That it comes from Bolcom is significant, for Bolcom - more than any of his contemporaries - is on a path that may well lead to the future of opera in this country. His thoughts on what he terms the ''American musical vernacular'' are detailed in the accompanying story; they are realized, with full dramatic effect, in every moment of ''McTeague.''

Bolcom's opera, to be sure, taps the resources of pre-existing musical genres. It is set in San Francisco at the turn of the century, and to conjure up a period atmosphere Bolcom alludes to concertina ditties, cowboy songs, cakewalks and the like. But these are never isolated from the rest of the score or showcased, like museum pieces, as objects perhaps worthy of contemplation. As befits a dramatic work about lust and violence, the music often erupts with shocking force. In terms of musical style, though, none of the gestures seems totally surprising. There is a balance here between tonality and its opposite, between lyric melody and crunching discord, between propulsive dance rhythms and weightless harmonic vapors. The old-fashioned bits are just a few threads among many that Bolcom has woven into a consistent fabric that feels right for the times. ''McTeague'' is modern opera, not postmodern.

The Chicago production features tenor Ben Heppner in the title role and soprano Catherine Malfitano as his miserly wife, Trina. Both of them, presumably, were cast with their physiques in mind. As novelist Norris told the story, McTeague is as big as an ox if not quite so dumb, and at first he is attracted to Trina in large part because of her fragile feminine beauty. Later he beats Trina to death, and the scene in the opera seems all the more gruesome because of the contrast in the singers' bodies.

Heppner and Malfitano, well-known on the international opera circuit, were in fine vocal form at the Oct. 31 premiere. So were mezzo-soprano Emily Golden as Maria, a cryptic charwoman infatuated with the idea of wealth, and baritone Timothy Nolen as Schouler, the jealous sidekick who turns out to be McTeague's worst enemy. The acting all around was credible; it was especially impressive in the chilly love scene during which Maria and Schouler reach orgasm by independently fantasizing about gold.

Altman, as noted above, was the stage director, but he also served as the opera's co-librettist; indeed, it was Altman who re-shaped Norris' novel into a two-act opera linked by quasi-cinematic flashback scenes, and his partner, Arnold Weinstein, simply came up with the characters' blunt, brutal words. Most of those words, but not Malfitano's, were clear as a bell at the premiere; it's probably a good thing that the entire text, as it unfolded, was projected on a screen above the proscenium.

''McTeague,'' expertly conducted by longtime Bolcom champion Dennis Russell Davies, will be repeated at the Civic Opera House on Monday and Thursday and Nov. 1 5, 18, 21 and 24.