"The River Project," by the Memphis Ballet MEMPHIS - The Mississippi River, famous in song and literature, has also inspired choreography. At the end of Kansas City Ballet's "Tom Sawyer," new last year, the dancers embodied it. Now Ballet Memphis has taken up the theme with "The River Project," a triple bill of new ballets honoring the Mississippi's cultural importance. On paper Ballet Memphis often looks like one of the country's most enterprising companies. I wish, for example, that I had been able to see its 2011 spring program of works, all by female choreographers; and the company is among the few directed and founded by a woman, Dorothy Gunther Pugh. Its current season is called "Taking Flight" and Ms. Pugh plans to follow the "River Project" with other works about the connections between American culture and the American environment. An introductory film suggests that the plan for these three new ballets was to reflect three zones through which the river passes: one ballet (Steven McMahon's "Confluence") on the central area around Memphis, one on the Delta and New Orleans (Julia Adam's "Second Line"), and another on - what? This third ballet (Matthew Neenan's "Party of the Year") proved the least obviously river-connected: its setting was a party in Los Angeles. This didn't make it a disappointment, however. Instead, it was both the evening's biggest hit and one of the most beguiling new American ballets of our day. All three works are set to musical collages, reflecting diverse heritages and histories. The score for Mr. McMahon's "Confluence" ranges from part of Dvorak's "New World" Symphony to Mahalia Jackson's recording of "In the Upper Room" to Mavis Staples's "Don't Knock." The stage action is introduced by a lone woman (Virginia Pilgrim), whose role is ambiguous: she may be the river, or the subsequent dances may be her memory. "Confluence" has lyricism and complexity; it suggests the passage of time and the growth of a local culture. It's a little nebulous over all, but there's real dance-making skill here. Ms. Adam's "Second Line" tries to catch the Delta's overlap of historical periods and its changes of civilization. Characters in baroque attire do some un-baroque things. Women kneel so that men can swing their legs over the women's heads. Later we have some bare-chested men and more overtly modern behavior. The music includes Rameau's "Fêtes d'Hébé," a Louisiana folk song and a traditional Haitian song, and ends with "When the Saints Go Marching In." At all points, the result is too diffuse. Mr. Neenan's "Party of the Year," subtitled "Victoria Avenue, CA, 12/25/70," is a success despite apparent odds. It has seemingly nothing to do with the Mississippi River; a program note says it's about a birthday bash on Christmas 1970 for a person in Isabel Wilkerson's book "The Warmth of Other Suns." This context promises characters and experiences that the ballet doesn't give us. But there is a piercing image, first shown in the introductory film, that becomes a core motif. The party is on the skids, and the pivotal character, danced by Rachel Shumake, has had more than a few too many from the start. The repeated sequence that makes such an impression is when Ms. Shumake slowly, heavily walks forward on flat feet, her head lifting and her throat visibly tense; then, with a contraction, her torso lurches right forward. By the time you've seen it twice, it clearly depicts a woman who knows with alarm that she's about to throw up. This could so nearly be gross - but its slightly stylized quality and its choreographic exactness makes it haunting, like a moment you've known yourself. Then, when it returns, at later stages of the party, it's shown from other angles. The fourth and final time it's given a change of inflection. This is a party that's merrily crumbling into near-chaos. The situation is explored through many different aspects - comedy, shame, poignancy, anxiety, energy - and a wealth of different characters. The final twist is that the most drunk character is transformed to a new exaltation of spirit. This is not at all the ballet suggested by Mr. Neenan's program note or Ms. Pugh's advance announcement - but so what? Straightaway Ms. Shumake seemed detached from the party; she's present but alien. The music's progression is from jazz (Nat King Cole), blues (Albert King, perhaps the most specifically Memphian music of the evening) and soul (Ray Charles) to (folk) Joni Mitchell. And, though the party seems to occur in one place with one set of people, this change of score takes us on a migration through America. When we reach Ms. Mitchell's "California," Ms. Shumake has survived more than one ordeal: she looks released and to have found her home. The party is all dancing and all delicious. Couples and threesomes succeeding one another, exuberant and socializing and intimate. The mixture of ballet, social dance and individual tics of behavior is irresistible, the footwork has point and detail, and the rich tiltings of torsos are juicy in the extreme. Some women spend some of the time supporting their men; this is a society in which men and women keep discovering new things about each other. The beauty of Ms. Mitchell's singing brings the ballet to an extraordinary climax; and Mr. Neenan's choreography matches it, as Ms. Shumake becomes expansive. The other characters, though, grow increasingly floorbound. This is the second exciting new work by Mr. Neenan I've seen in three months. "Switch Phrase," for Ballet X, was seen in August at the Vail Festival. He does not present himself as a pure-academic ballet classicist, but he is emerging as one of today's foremost dance poets of American behavior and society. An earlier version of this article, in one instance, misspelled the surname of a choreographer. He is Matthew Neenan, not Neeman.