BEND, Ore. – The fact that trees are wearing tutus is not the only remarkable thing about Arbor Ballet, an installation and performance, conceived by public artist Helen Lessick, that premiered in Bend, Oregon on October 5. It’s got some highly original, science-based music to go with it.

Lessick outfitted ten of the trees in the Central Oregon Community College (COCC) arboretum with organza tutus, placed high on their trunks. Their “dance” is the movement of their leaves, twigs, and branches as the breeze plays through them; and they’re accompanied by instrumental music of a unique kind. Cellist Emma Chaput performs Song of Our Warming Planet by Scott St. George and Daniel Crawford, a musical translation of today’s leading environmental issue.

The Song is not merely an expression of concern; it’s quite literally a transmission of data. St. George and Crawford, professors in the geography department of the University of Minnesota, created the piece in 2013 by translating climate data—specifically, the alarming warming rate of the planet as it has been traced over the years—into musical notes, as they describe in a scientific paper.

The researchers assigned a very low note to the coldest temperature on record between 1882 and 2012, according to the records of NASA’s Goddard Institute of Space Studies. That chilly date was 1909; thereafter, “each ascending semitone [ in the composition was] equivalent to roughly 0.03˚C of planetary warming,” they write. Needless to say, the music slowly rises in pitch, overall, as the piece goes forward and the planet warms.

Contrasting their approach with the rather dry effects of charts, graphs, and statistical lists, St. George and Crawford note that “music…can exert a powerful influence on human emotions. Because of these characteristics, sonification—the transformation of data into acoustic signals—may have considerable promise as a tool to enhance the communication of climate science.”

Arbor Ballet accompanies a retrospective exhibition of photographs and other documents of Lessick’s work, under the title CANOPY: On Helen Lessick’s Trees. The show, in the Pence Gallery of the Pinckney Center for the Arts at COCC, includes photos of many of Lessick’s site-specific installations, along with sculpture, artists’ books, installations, and works on paper.

It’s all part of a celebration of the 30th anniversary of House for Summer, Lessick’s living-tree sculpture growing in Portland’s Hoyt Arboretum.