Spring is the season of change, and ballet companies are no different. Some changes are obvious — principal dancer Ian Hussey is retiring on Sunday after 15 years as a professional. The company presented a world premiere Thursday night, when it presented its season finale at the Academy of Music.

Others are more subtle. Ballet company contracts are annual, so in the fall, we will see a different roster of dancers.

But the 2018-19 version of the Pennsylvania Ballet is going out on a high note this week with a trio of ballets: One the company has danced before, a new work, and a Jerome Robbins piece that has been around for decades but that has never been in the Pennsylvania Ballet repertoire.

In Philadelphia, we’re lucky to see lots of new ballets, many courtesy of BalletX. But in an era when so many want to break out of the box, Trigger Touch Fade by Finnish choreographer Jorma Elo (who is also resident choreographer at Boston Ballet) is special as a pure work of ballet with classic footwork and beautiful lines, set to lovely music by Haydn and Bach.

Pennsylvania Ballet dancers Oksana Maslova and Zecheng Liang in Jorma Elo's "Trigger Touch Fade."
Alexander Iziliaev
Pennsylvania Ballet dancers Oksana Maslova and Zecheng Liang in Jorma Elo's "Trigger Touch Fade."

Danced in jewel-toned costumes, it is a very leggy ballet, with many long leaps, stretches, and even turns with deliberate positions to highlight the limbs.

It’s a beautiful, fun, and very classical work that highlights the talents of dancers such as Oksana Maslova, with her long extensions, and Jermel Johnson, with his impressive jumps.

The lighting is long beams that often crisscross the stage, a cool design by Brad Fields. But it occasionally hovers too low over the dancers’ heads, seemingly limiting how high they might jump.

The Pennsylvania Ballet first performed Christopher Wheeldon’s DGV: Danse à Grande Vitesse in 2015, but it’s an exhilarating work that bears repeating. Set to Michael Nyman’s Musique a Grand Vitesse, it is an homage to the French high-speed TGV train. Sometimes the dancers are passengers, sometimes they’re the train. They take time to build up speed, but then they’re off.

Pennsylvania Ballet dancers Yuka Iseda and Ian Hussey in Christopher Wheeldon's "DGV."
Alexander Iziliaev
Pennsylvania Ballet dancers Yuka Iseda and Ian Hussey in Christopher Wheeldon's "DGV."

A touching moment was one of Hussey’s last dances, a lovely, fluid duet with Yuka Iseda. He will alternate performances of DGV and Glass Pieces throughout the run, dancing both before taking his final bow on Sunday.

Robbins’ Glass Pieces was created in 1983 but is new to the Pennsylvania Ballet. If DGV is a piece about a train, Glass Pieces — set to music by Philip Glass — looks like it is set in Grand Central Station, but in a good way.

Masses of dancers in different-color practice clothes hurry through the space until finally a pair in matching costumes find each other and dance together. But soon the crowd overcomes the scene again, until another couple find each other.

The backdrop looks like a giant piece of graph paper, and considering the paths the many dancers took, one assumes such paper was necessary in setting the ballet.

Steven Spielberg is making a new West Side Story, with choreography courtesy of Justin Peck (whose work the Pennsylvania Ballet has danced). But if you want to see the work of the original choreographer, the movement in Robbins’ Glass Pieces has more than a touch of Jets and Sharks.

Pennsylvania Ballet in Jerome Robbins' "Glass Pieces."
Alexander Iziliaev
Pennsylvania Ballet in Jerome Robbins' "Glass Pieces."

DANCE REVIEW

DGV, Trigger Touch Fade, Glass Pieces

The Pennsylvania Ballet repeats the program at 7:30 p.m. Friday, 2 and 8 p.m. Saturday, and 2 p.m. Sunday, at the Academy of Music, 240 S. Broad St. Tickets: $29-$154. Information: 215-893-1999 or paballet.org