It has lasted. Encouraged by a whole host of seminal new music figures including John Cage, Essential Music's John Kennedy and Charles Wood have recentered the American experimental tradition within the Manhattan scene, reawakening Downtown's awareness of its roots. Through contextual programming and a vigorous combination of the new and old, they have relinked the present generation of composers with a thread that goes back to Ives and Cowell: music as a form of cultural and environmental consciousness. While Essential Music has cultivated a percussion-based repertoire, it adapts to whatever repertoire or project is at hand, and has magically mutated to include an accordion, string ensemble, or even a 112-musician orchestra. And Essential Music's concerts have attracted a larger and more enthusiastic audience each year.

One of the group's most heroic feats is continually rescuing groundbreaking but forgotten American composers from obscurity. No one has more deserved and needed rescue than Johanna Magdalena Beyer (1888-1944), a Leipzig-born composer who emigrated to New York in 1924 and became Henry Cowell's student and secretary, taking over much of his business during his prison incarceration. A proto-minimalist of startling originality, Beyer used electric tones, glissandos, noise, repetitive structures, and quotation in musical fabrics that still seem bizarre today, even after the 1970s rendered some of her techniques commonplace. Music of the Spheres -- dating, astonishingly, from 1938 -- was intended as part of a satirical political opera called Status Quo. The piece calls for a gradual accelerando from 52 quarter notes per minute to 208 over a 54-measure period, and Beyer suggests the option of using electric instruments rather than strings. Beyer was all but forgotten when Essential Music revived her music in 1988.

Percussionists that they are, Kennedy's and Wood's own aesthetics are earthy and material-oriented: that is, each piece usually revels in some type of appreciation of a particular medium, whether sandpaper blocks, drumheads, ratchets, even rocks. Kennedy's music ranges from the tumultuously irreverent to the quietly spiritual, and Chant marks the latter end of that spectrum. The piece never swerves from its meditative focus, yet the sparse beginning and end sections are carefully notated, while the central section is based around a common set of rhythmic cells that each performer makes his own path through at his own tempo.

A true mainstay of the avant garde, Robert Ashley is better known for his operas (Perfect Lives, Atalanta, Improvement: Don Leaves Linda) than for his infrequent instrumental works. In memorium...Kit Carson, in fact, is an opera, 1963-style: conceptual, open-ended, realizable in a myriad ways. It was one of four memorial pieces (the others being a quartet for Esteban Gomez, a concerto for John Smith, and a symphony for Crazy Horse) written in the most abstract manner possible, with simple graphic scores that allow musicians to work their way through various definitions or parameters with much left up to the performers. In Kit Carson, excerpted here, the performers charted what groups would enact what kind of events at each point in time, and at what points the group would interact. One of Ashley's early anything‚goes scores, Kit Carson predates even his notorious Wolfman of 1964.

Like in memorium...Kit Carson, Christian Wolff's Merce (named for the dancer Merce Cunningham) is very free. Wolff, of course, was the precocious youngest member of the New York School around John Cage, who veered over the years from game‚oriented chance music to Marxist political songs. Merce, from 1993, is indicative of Wolff's return to more purely musical methods, though unlike his early works, much of the piece is explicitly notated. It consists of solos, duos, trios, quartets, and so on, which can be played in any order, in any fractions thereof, and at the same time.

Also from the generation of Ashley and Wolff, Malcolm Goldstein is an improvising violinist whose delicate, Vermont-inspired scores have not received their proper due in the urban new-music scene. The Seasons is perhaps his magnum opus, a concert-length work performed over tapes of environmental sounds made at his Vermont home over the course of the year. Over this restful background the performers, including here Ben Neill, follow a series of graphic, verbal, and occasionally conventional notations to create a noisy, yet mellow meditation.

Peter Garland is one of American music's unsung heroes from a younger generation; from 1971 to '91 he published the journal Soundings, devoted to American composers of great originality -- Nancarrow, Lou Harrison, James Tenney, and many others -- often publishing their works and writings for the first time. For all the fiery rhetoric of Garland's writing, his own music is surprisingly mild and lovely. He draws endless melodies from just a few pitches without quite repeating himself, in a style that seems postminimal but is inherited from Lou Harrison and Henry Cowell rather than Steve Reich or Philip Glass. A Green Pine is typical: a lovely melody in pure Mixolydian scale on F, harmonized with parallel triads in simple but ever‚changing rhythms. The text, Drinking Wine by T'ao Ch'ien (365-427), is on a theme close to Garland¼s heart.

From the very beginning, Essential Music has generously included me within the American experimental tradition they champion. In fact, the percussion pieces they have asked me to write have accelerated the development of my rhythmic language, which is drawn from the polytempos and isorhythms of Conlon Nancarrow and the pulse-shifting of Hopi, Zuñi, and Pueblo Indian music. For my Snake Dances I use tempo melodically, moving along a scale of durations to create motives as one would move along the keys of a piano. Snake Dance No. 2 alternates between sections of rhythmic "poetry" and "prose," and is gratefully dedicated to Chuck and John.

Charles Wood is one of New York's most tactile composers, an artist in love with rough, raspy, natural sounds. His performances have included tea kettles brought to boil onstage and rocks hit together in intricate rhythmic patterns for 45 minutes until the performers are covered with a fine layer of dust. Land's Shadow (1988) is one of his most ambitious works, full of coffee cans scraped across glass tables, huge cylinders turning as rocks rattle inside, sandpaper blocks rubbed together, the clicking of spikes on rotated wheels. To create the piece Wood set up an open structure partitioned according to the Golden Section (1:1.618..., a proportion found in natural processes and Greek architecture). With its joyous openness to new sounds, its disdain for performance conventions, and its attentiveness to structure and the experimental tradition, the work sums up what is most essential about Essential Music.

© Kyle Gann/Monroe Street Music.