It was genuinely heartwarming to see the Joffrey Ballet back at Wolf Trap Tuesday night after an absence of nine years. Given the company's deliberately populist approach -- in large measure a reflection of co-founder and Artistic Director Gerald Arpino's aesthetic outlook -- as well as its accent on youth and its emphasis on American themes and artistry, the Joffrey seems perfectly matched with Wolf Trap's own mission as a national arts park. It was no accident that the troupe was the first ballet company to appear at Wolf Trap in its opening summer of 1971, and that it returned there annually for a decade.

This was also the company's first performance in the Washington area since its recent precarious bout of brinkmanship, in which a rift between Arpino and the company board, together with financial setbacks, threw the company's future into deep doubt for a time. Fortunately, the crisis has passed and Arpino's absolute artistic prerogatives have been reconfirmed. A certain sigh of relief seemed fitting at the sheer fact of the fulfillment of the Wolf Trap engagement.

For the occasion, the troupe presented a program of three ballets, each of which represented an important and characteristic strand in the Joffrey repertoire: "Billy the Kid," the Americana classic with choreography by Eugene Loring and a landmark score by Aaron Copland, dating from 1938 but acquired by the Joffrey only two years ago; "Lacrymosa," an ambitious first ballet by company dancer Edward Stierle, dedicated to the memory of the late Robert Joffrey; and a revival of Arpino's celebrated rock ballet of 1970, "Trinity."

Stierle's ballet began as a solo he constructed for himself for the 1986 International Ballet Competition in Jackson, Miss., and which helped win him the meet's junior division gold medal. It was then developed, in a workshop setting, into a piece for the Joffrey II Dancers that premiered in 1988 and was further expanded into its present form the next year.

"Lacrymosa" has much to recommend it, especially as a debut choreographic effort. It follows no hackneyed models, but rather treats a serious theme in a very serious manner, in the process coping sensitively with a challenging musical score -- recorded excerpts from Mozart's Requiem -- that might easily have overwhelmed the dance. Indeed the parts of the work -- essentially an extended dirge -- handled in choric fashion are more impressive than the overwrought solo passages for Stierle, as a sort of chief mourner, and the couple in black, Jodie Gates and Douglas Martin. The swirling ensemble sequences, using arched arm and upper-body shapes reminiscent of Jiri Kylian's ballets, are apt visualizations of turbulent grief. The work's flaws are mainly those of youth's excess -- a multiplicity of climaxes that dilute their own emotional impact with redundancy, and a reaching for poignancy that sometimes looks merely florid. But there's assuredly promise here, and more than reason enough to await future Stierle endeavors optimistically.

"Billy the Kid" seemed much more deeply comprehended by the dancers than it did at Kennedy Center last year with the same cast of principals. Tom Mossbrucker's Billy now more effectively contrasts the innocence of the opening scenes with the callous vengefulness of the adult outlaw, and his duet with Gates, as the Sweetheart, has more emotional resonance. Martin was a stalwart Pat Garrett, and Peter Narbutas an appropriately fishy Alias. There are still many details of the Joffrey version -- as staged by Patrice L. Whiteside, with reproduction of the steps from Labanotation by Virginia Doris -- that lack the trenchancy of the American Ballet Theatre production. Still, the power and originality of the work -- in its opening and closing friezes of struggling pioneers, its cinematic structure, its sharp characterizations and such remarkable touches as the expressionistic group of hooded mourners surrounding Billy's fallen corpse -- comes through.

"Trinity," which had its world premiere in Berkeley, Calif., looks almost quaint today as an evocation of '60s mystique. What it evokes is not so much the era itself as an image many Americans had of themselves at the time and in retrospect. The music by Alan Raph and Lee Holdridge -- a radical departure for ballet in those days -- is an odd mixture one might call evangelical rock, with its hymnlike brass fanfares and echoes of Benjamin Britten in the sugary choral writing. Today's dancers, if accurately sampled by Tuesday night's cast, appear to have lost touch somewhat with the twist- and frug-like aspects of the choreography, and they seem a bit uncomfortable with the whole ballet-cum-go-go idiom. Nevertheless, the work's naive messianic fervor and breakneck athleticism still make points with a contemporary audience, as the Wolf Trap reaction demonstrated. Though the connection between George Bush and flower-power hippies seems tenuous at best, the ending of the ballet -- in which the dancers exit leaving an array of lit candles on the darkened stage -- somehow foreshadowed the president's "thousand points of light."