Composer Michael John LaChiusa's ambition is as big as Texas, which seems appropriate for his sprawling and terrific new musical, Giant. Adapting Edna Ferber's Pulitzer-winning 1952 novel (the basis for the 1956 film starring Rock Hudson, Elizabeth Taylor, and James Dean), the composer has crafted one of the finest new American musicals in recent memory. (The show runs through Dec. 2 at the Public Theater.)
The story centers on rancher Jordan ''Bick'' Benedict (Smash's Brian D'Arcy James, with a drawl and an earth-bound solidity) and his well-read, well-heeled Virginia wife, Leslie (the gorgeous and crystal-voiced Kate Baldwin), who immediately feels out of place in her new Texas home in the 1920s. In short brushstrokes, LaChiusa and book writer Sybille Pearson establish surprising depths in this unlikely pair. Though he's a committed Texan, he's no prairie rube: He spent two years at Harvard and picks up on her Emerson quotes. Leslie, meanwhile, envisions a move West to live out some of the daydreams she's had in her father's study, ''and unlike here there's a great unknown just waiting there.''
Once on Reata, the Benedict ranch, the show's canvas widens to include Jordan's ranch neighbors, the Mexican workers, as well as Jett Rink (PJ Griffith), a good-looking but immature hand who soon strikes out on his own and takes an (unrequited) interest in Leslie and, later, in her tomboy daughter, Luz (a feisty Mackenzie Mauzy). Luz' brother, Jordy Jr. (a quietly powerful Bobby Steggert), emerges as a dutiful and bookish lad who finds it hard to connect with his father given Bick's stalwart devotion to the ''heartbreak country'' of Texas particularly after Jordy Jr. falls for Juana (the lovely Natalie Cortez), a Latina on the ranch who longs to be a teacher.
Though it clocks in at three hours and 15 minutes, Giant moves with brisk efficiency through its decades-spanning story under the capable direction of Michael Greif. One secret to the pacing is LaChiusa's clever deployment of songs to advance the plot. And he rounds out the central Benedict family drama by giving supporting characters their one opportunities to shine. In fact, some of the production's strongest numbers include ''He Wanted a Girl,'' a jilted-woman ballad sung by Jordan's big-boned childhood sweetheart Vashti (a strong Katie Thompson) and ''Jump,'' a spirited up-tempo ensemble number at the top of the second act featuring young Luz and her then-teenage peers both Mexican and Anglo.
In works like The Wild Party and Marie Christine, LaChiusa burst on the theater scene as a serious-minded student of Sondheim with a somewhat allergic reaction to traditional melodies. But here he rolls out hummable song after hummable song, drawing on musical traditions as various as classic Broadway show tunes (Rodgers and Hammerstein particularly), Aaron Copeland orchestral works, Mexican folk music, and Native American percussion. The score is richly and satisfyingly complex, with each major character getting a musical motif or style. (Jett's tunes, for instance, have a syncopated jazzy feel befitting a man who rejects traditional ranching for the urban life made possible by oil drilling.)
In the end, though, it is the story and its epic but human sweep that will draw you in. As in Ferber's novel, LaChiusa touches on themes that are both universal (the conflict between fathers and sons, the inevitability of death and loss) and particular (anti-Latino bigotry, Texas' transition from ranching to an oil-based economy). The overarching issue: Just how susceptible are we to change? By the end of the show, Bick and Leslie are middle aged and on a precipice in their relationship. They've grown in some ways, but they've also stubbornly clung to tradition and bad habits. Through it all, they've remained side by side, reinforcing the value of forging and maintaining connections despite the vicissitudes of life. ''I don't want false hopes,'' Leslie sings. ''I just want us to keep talking.'' And, God willing, to keep singing too. A
(Tickets: PublicTheater.org or 212-967-7555)