The American Dance Festival‘s final week each summer season includes a program that both commissions the future and preserves the past — and gives the young dancers of the Festival’s six-week school a showcase. This year’s Past/Forward in Duke’s Reynolds Theater looks back on Twlya Tharp’s Sweet Fields, forward into Martha Clarke’s Études for Italy, and at the immediate present with Baulareyaung Pagarlava’s Landscapes 2011 ADF. Past/Forward has become a highly anticipated event each year, and nothing disappoints this season. All three dances offer pleasures.

Not the least of these is the lithe, casually energetic and often exuberant dancing. As usual, what the students lack in seasoned control and nuance, they make up for with fire and grace. They dance with an infectious generosity of motion that arises from their joy at doing what they love to do. This was quite noticeable in Sweet Fields, which was last seen here three years ago, as performed by the Aspen Santa Fe Ballet. In the current version, the dancers move more freely, less self-consciously. It appears to thrill them to successfully execute Tharp’s demanding footwork, sudden reversals of direction and bravura pace, and their emotion feeds the emotions of the dance, which is set to a series of hymns from the Shaker tradition. I enjoyed this more than the exquisite, cooler performance by Aspen Santa Fe.

Martha Clarke is a dance theatre genius, and even in an early-stage-of-development production, her work fascinates, with both image and action. Études for Italy in its full, finished version, will actually premiere next year, at La Scala, in Milan. But there is enough here that one hopes the ADF will present the full piece next season. The students did a marvelous job on the physical aspects of the dance, but more experienced people will undoubtedly intensify the theatre aspect, which needed a bit more smoldering heat.

Bulareyaung Pagarlava’s Landscapes 2011 ADF gets off to a most unpromising start, with each and all the cast members coming before us in ones and twos to tell us their names and something about themselves and to act nutty. In addition to the 16 students, Tao Ye and Duan Ni, of TAO Dance Theater, take part. But then the boisterous gang starts to dance — galloping to the William Tell Overture, no less — wonderful dances with all sorts of activity, dances with patterns, dances with music, dances with humor and pathos and mystery. The performers wear bright costumes (by John Brinkman) when they wear anything at all, and bright socks. Silly, fun, colorful socks on gorgeous strong legs in crazy attitudes under David Ferri’s active, colorful lighting — it is as refreshing as a carbonated drink on a hot day.

Past/Forward continues July 19 and 20. See the sidebar for details. The 2011 ADF closes this weekend with the Paul Taylor Company, July 21-23. See our calendar for details of that.