"I have always considered music to be a very strange substance, a substance endowed with magical properties," composer George Crumb has said. In unlocking these mysteries, he treats tionally: Pianos are strummed, plucked and pounded; violins are played with thimble-covered fingers and hair-slackened bows; a struck gong is submerged in water; instrumentalists shout, whistle, cluck strange phonetic syllables -- even count in foreign languages.

Crumb embraces the real and the surreal; they coexist and collide in sounds mighty as a seismic rumble, gentle as a breeze whispering through an aeolian harp. expression communicates. As he's put it, "Music is tangible, almost palpable, and yet unreal, illusive . . . the important elements -- the spiritual impulse, the psychological curve, the metaphysical implications -- are understandable only in terms of the music itself."

These lofty thoughts come from a soft-spoken man of 56 with the smoothest of West Virginia drawls that puts the "ar" back in Washington, site of several Crumb premieres. He'll offer yet another in person at the Kennedy Center Wednesday night, for a special concert of his works.

Crumb, who has taught composition at the University of Pennsylvania for the past 21 years, recollects fondly what it was like growing up surrounded by music at home (from his clarinetist father and cellist mother) and in the Charleston community. "We had chamber music around the house all the time," he recalls. "My father was a band conductor for a while, so I heard all that repertory. Both of my parents were in the local symphony orchestra, and I heard the church music around the area, and some of the country music -- I couldn't escape this," he adds with a chuckle.

At age 9 he started playing piano; composing followed the next year and stayed with him through high school, becoming serious business at Mason College in Charleston, and for advanced degrees at the universitys of Illinois and Michigan. Mahler, Debussy and especially Barto'k exerted the strongest influences at first. In search of his own voice, Crumb got an unexpected inspirational jolt by way of the Spanish poet Federico Garcia Lorca, while a doctoral candidate at Michigan.

"I heard a fellow student's setting of Lorca; his images and total poetic vision seemed to be something I could work with musically. It was at Ann Arbor, and the poem was 'The Song of the Boy Wounded by the Water,' which I later set in the 'Songs, Drones and Refrains of Death.' "

This piece, completed in 1968, was the fourth of 8 pieces with texts by Lorca he wrote between 1963 and 1970, a period when he fully established his identity as a creator of unusual juxtapositions of instrumental and vocal timbres. The first, "Night Music I" for soprano, piano, celesta and percussion, only hinted at the powerful interaction between verse and music Crumb would produce. "Songs, Drones and Refrains of Death," with a complement of baritone voice, electric guitar, electric double bass, electrified piano and harpsichord and two percussionists is the largest and longest in the Lorca cycle. It is also his personal favorite ("It was so darn hard to write, maybe that was a factor," he explains).

In "Ancient Voices of Children" (one of Crumb's best known pieces), lyrical melodies are confronted by hysterical flights of soprano vocalise sung into an amplified piano to generate spectral reverberant waves. Mandolin, oboe, harp, electric and toy piano and percussion provide the primordial edge in his Lorca finale that premiered at the Library of Congress in 1970.

Crumb's works from the '60s contained two ingredients prominent today: West Virginia artifacts and instrument amplification. In his Pulitzer Prize-winning "Echoes of Time and the River: Four Processionals for Orchestra" (1967) performers bark out "Montani semper liberi" ("Mountaineers are Free?"), Crumb adding the question mark, he puns, "for a little motto effect." Mountain instruments he's used include banjo (played bottleneck style), musical saw ("Ancient Voices"), jug and jew's harp. "A Haunted Landscape" (1984) introduced the hammer dulcimer as part of his ever-growing arsenal of percussion.

As for amplification, Crumb not only likes it, but feels it's crucial to communicate his ideas. "It helps project those very small sounds," he says, "but I also like the power of amplification without distortion. Idiomatically, it tends to make the instrument sound different."

Case in point: "Black Angels: Thirteen Images From the Dark Land" for electrified string quartet. The two movements named "Night of the Electric Insects" have some of the most terrifying sounds ever written, and the screaming strings are guaranteed to scare at least the bejabbers out of any unprepared listener. Numerological and diabolical references abound. Tritones (known as the Diabolus in musica), trills ("Trillo di diavolo," or Devil's trill, derived from Tartini and grotesque sustained tones are central to this God versus Satan polarity, in which the black angel undergoes a journey of the soul: a fall from grace, spiritual devastation and ultimate redemption. A quote from Schubert's "Death and the Maiden" Quartet fades in like a viol consort dirge. Crumb inscribed his score: "finished on Friday the Thirteenth, March, l970 (in tempore belli)."

The mystical relation of numbers, traceable to Bach and Barto'k, he believes are part of our culture and for him stem from his readings in astronomy, archeology, religion and -- to a small degree -- astrology. "I think all of what one reads probably turns up in the music in some form. That's happened with me. Part of your way of looking at the world and music reflects this."

Crumb's first two volumes of "Makrokosmos" for amplified piano certainly do. Volume I's 12 segments depict the Zodiac sign, getting to the essence of each symbol through mysterious muted tones, harmonics and plucked notes. A chain resonates across the strings in one section; a metal plectrum scrapes the windings on the bass strings in another. He carries some titles out literally, writing the muic for "Crucifixus" (Capricorn) on cross-shaped staves. "Spiral Galaxy" (Aquarius) resembles an upside down, backward bass clef. Each section also has a set of unidentified initials belonging to Crumb, other composers, performers and friends born under the appropriate sign. Consider it his whimsical way of saying, "Scorpio, and my name is George."

While he is very much concerned about the intellectual content of his compositions, Crumb remains a non-ivory tower artist, responsive to the world around him. "Night of the Four Moons" arose from his ambivalent attitude toward the Apollo 11 mission that put man on the moon. Closer to home, "Voice of the Whale" for flute, piano, cello/antique cymbals, aside from conjuring the lonesome song of the humpback whale, makes a point: Crumb orders the performers to wear half-masks indicating dehumanized natural forces at work. "An Idyll for the Misbegotten," for flute and three drummers (1985) re-examines our ecosystem. "The misbegotten refers to mankind in the world as being a little illegitimate these days," he describes, "because he's upsetting the balance in nature."

The Terrace Theater's musical portrait of George Crumb will soft-pedal the philosophical side of his work. Participating musicians mezzo-soprano Jan DeGaetani, pianist Gilbert Kalish and violinist Paul Zukovsky are unsurpassed interpreters of 20th-century music in general, and Crumb in particular (DeGaetani has recorded just about all his pieces suited for her range). Kalish promises to give a powerful reading of "Gnomic Variations," which is not a depiction of a folklore creature, but of the pithy succession of ideas challenging the pianist to make rapid transitions from key fingering to string striking.

However, it's the vocal works slated that will have a particular appeal. "Apparition: Elegiac Songs and Vocalises for Soprano and Amplified Piano" was written for DeGaetani and Kalish in 1979. Crumb has taken his usual composer's liberty with the text from Walt Whitman's "When Lilacs Last in the Dooryard Bloom'd." Though voice and piano are not treated traditionally, the prominent lyricism is more in keeping with this standard chamber format and may surprise some.

The biggest treat may be the world premiere of three unpublished songs, dated 1947, when Crumb was a senior in high school. "The style will astound everybody," he says wryly, "but we thought it would be fun to do as kind of a curiosity piece. I think a little Rachmaninoff comes in there, and probably some Debussy. They're solidly tonal and the texts are by Sara Teasdale and Robert Southey."

In dusting them off, he found awkward measures typical of student works. "I touched them up just a bit to make them more performable, trying not to change the kind of naive sound they have."

Take me home, country roads.