Every so often, Meredith Monk summons all her many talents - as composer, choreographer, singer, dancer, director - and weaves the lot of them into a major theater piece. The latest is a leisurely, gentle, and fascinating show called''Specimen Days,'' running through early January at the Public Theater. Rooted in the past and clearly concerned about the future, it plunges through American myth and history like a multimedia time machine.
Not surprisingly, ''Specimen Days'' is based on Miss Monk's unique musical style, which informs the entire sound and structure of the work. For those who have never heard it, this is a hard style to imagine, incorporating a wide variety of tones and textures not normally found in Western music, ranging in effect from folksong to birdsong.
Though she originally developed her techniques through experiments with her own voice, Miss Monk has been writing for an ensemble lately, and in ''Specimen Days'' both choral and solo singing are artfully integrated into the flow of the performance.
This could portend further popularity for the unique Monk artistry, which is currently in evidence on a splendid new record called ''Dolmen Music'' (ECM-1- 1197) and will regale a wide audience when Monk and company set off next month on a major tour of the West Coast and Europe.
''Specimen Days'' takes its title from Walt Whitman, and most of its important images come from Whitman's era, around the time of the Civil War. In many scenes, the show seems concerned with the miseries people cause themselves, a theme which is eloquently summed up by the looming memory of a war that pitted brother against brother. At one point the stage is covered with miniature tents, like a battlefield at dawn, until a giant cannonball comes careening through the room and mows them down. Later, on a movie screen, a turtle stalks through deserted city streets, and it is clear we have left the Civil War for World War III - when only the thickest of skins will have any chance of surviving.
''Specimen Days'' comprises far more than melancholy memories and apocalyptic forebodings, however. Most of the dominant images are attractively nostalgic, recalling a time that seems to have been more inviting in many ways, when life moseyed along at a turtle's comfortable pace. Families group for photographs, gather around dinner tables, and care for their loved ones.
They are specimens all, and we are invited to examine them in all their bittersweet, sad-glad, good-bad complexity.
Yet there's no mistaking a delicate sadness at the heart of the show. In the very first scene, the actors are presented to the audience like figurines at a gallery. Later, in a dark echo of this moment, a black slave is displayed on an auction block. And in the end, there's nothing to see but that lumbering turtle, inheriting the earth after the last of all civil wars.
The images of ''Specimen Days'' are linked by Miss Monk's own presence, as a character loosely based on composer Louis Moreau Gottschalk. Elegantly attired in formal clothing, she sings evocative solos at a grand piano, does a shuffle-off-to-everywhere dance, and takes her place in unexpected vignettes.
This device is not entirely satisfactory, as it never quite settles Miss Monk as either a master of ceremonies or a participant in the action. It's a compromise, and it looks like one, especially by comparison with the other dramatic elements of the show, which are thoughtfully conceived and smoothly executed.
There is no gainsaying the musical richness of the work, though, from its keening start to its clamorous finale, culminating in a poignant collision between one of Miss Monk's most exquisite compositions - the ''Turtle Dreams'' waltz - and the insistent sound of Gottschalk's piano.
Among the regular Monk collaborators in the cast are Andrea Goodman as a Southern mother, Robert Een as a Northern grandfather, and Paul Langland as, among other things, a tree. Ronnie Gilbert of the Winter Project and Nicky Paraiso, a colleague of Jeff Weiss, are some of the other performers who have mastered Miss Monk's unusual vocal and gestural demands. Robert Withers made the films starring the aforementioned turtle, whose name is not listed in the program.