This happens to be the 80th season of the Jacob’s Pillow Dance Festival. But anniversary or no, the venerable theater and school in Becket, Mass., always has a reason to celebrate. In fact, dance itself is celebratory ; lithe young artists leap, twirl and intertwine with endless inventiveness, using music from all walks of life and from the pages of history up to the minute.
   Today’s opening benefit, beginning at 5:30 p.m., is a microcosm of what takes place in the Pillow’s theaters, studios and exhibition halls. The evening program offers a forecast of the season’s range of nationalities, styles and periods, as well as of its dancers and choreographers.
   Michael Corder, director of dance at the English National Ballet School, arrived early to choreograph a piece for the Pillow’s ballet students.
   Today, it receives its premiere. What does this exercise reflect about the season? Keywords: ballet (a category of dance), students (category of performer), international (artist got a visa) and premiere (brand new).
   Circa, an Australian dance and circus arts company, will preview its June 20-24 programs (to be in the smaller Doris Duke theater), which features dances expanded by hoop-twirling and rope-trapeze work. Representative keywords for Circa: circus, aerial, modern, international.
   A duet by Mimulus gives a foretaste of that Brazilian company’s appearances in the main Ted Shawn Theater, also June 20-24. Featured on those dates is the U.S. premiere of “Por Um Fio” (“ By a Thread” ), whose costumes and choreography explore works of Arthur do Rosario, a lifelong asylum inmate who re-created his thoughts in wood and embroidery.
   The artistic director of Mimulus, Jomar Mesquita, travels to collect social dance styles, including samba, tango and salsa. Keywords: social dance, hot, international, premiere.
   David Hallberg, principal dancer with the American Ballet Theatre and Bolshoi Ballet, will perform “Kaburias,” Nacho Duato’s wild solo, in which Hallberg wears a voluminous Martha Graham-type skirt and no top. From Aug. 1 to 5 Hallberg will join choreographer/ dancer Jonah Bokaer in three U.S. premieres, with either minimal costumes or quantities of material. Keywords: stars, exotic, magnetic. SALUTING SHAWN
   Add up the words ballet, students, international, premiere, circus, aerial, modern, social dance, hot, stars, exotic, magnetic — in a single evening — and it’s easy to see why Pillow director Ella Baff is excited about her 14th year of introducing each show with her charming invitation, “Let’s dance!”
   The anniversary year is of the Pillow’s founding by modern dance pioneer Ted Shawn. After separating from his wife and dancing partner, Ruth St. Denis, Shawn took over an abandoned barn on the Becket site to use as a retreat for his company of Men Dancers, an all-male ensemble that showcased a muscular and masculine dance style. As dancer Frederic Franklin put it, “There were no ladies to be lifted around.”
   “The Men Dancers: From the Horse’s Mouth,” a fitting homage to Shawn (July 11-15 ), has a rotating 20-member cast of great male dancers and choreographers who will perform solos and share personal stories. In the cast are Dance Theatre of Harlem founder Arthur Mitchell; tap star Jason Samuels Smith; Trent Kowalik, an original Billy in the musical “Billy Elliot” ; choreographer Lar Lubovitch Jr.; and former New York City Ballet principal Jock Soto.
   Franklin, an honored dancer born in 1914 who has lifted some legendary ballerinas, made his crack about lady-lifting in a 74-minute documentary film about the Pillow, “Never Stand Still,” to be shown in a new Sunday afternoon series July 15 and 29 and Aug. 19. Narrated by Bill T. Jones (who will appear July 25-29 ), the film’s generous clips of dance and interviews, some with dancers’ voiceovers, fill in possible gaps in knowledge so viewers can understand the past and reconsider the future.
   There is a clip from 1955, when Shawn brought the Royal Danish Ballet for its U.S. debut. In those days, the theater was already indoors, but its atmosphere was tentlike, and performances weren’t much fun if it rained or you forgot your bug repellent. OTHER ATTRACTIONS
   Baff has no trouble listing what she or anyone else could do at the Pillow without setting foot in a theater. She would watch films and videos of dance available in the barn gallery, go into a studio to watch dancers train, walk the nature trail, listen to the free talks with writers and fi lmmakers and eat in the café .
   “You can bring your family, your dog, your picnic, and meet interesting people even if you can’t afford a ticket,” she said. “It’s not just about performances, it’s about sharing dance history through archives. You can come into the archives, see exhibits, access video from long ago or from the other day’s performance. There are free performances on the outdoor stage, some by people who later became part of the festival. Students perform every Saturday. For me, it’s completely thrilling.”