George Gershwin said he wanted to "write songs for young girls sitting on fire escapes on hot summer nights in New York and dreaming of love."

Gershwin, who died at the age of 38 in 1937, probably wouldn't have been surprised to find that his songs, at least the best of them, have become immortal, part of our collective consciousness. He might even have expected it. He knew he was good.

Possibly he would have been intrigued, though, to learn that choreographers have fashioned entire ballets out of his songs. The Martha Graham Dance Company presented its Gershwin dance, "But Not For Me," in 1998. And before that, in 1970, George Balanchine, who knew Gershwin in the composer's last years, created "Who Cares?" for the New York City Ballet, incorporating 16 songs, dressed up in orchestrations by the American composer and arranger Hershy Kay.

To kick off the final weekend of the 37th edition of Sommerfest — and his farewell as the festival's artistic director — Andrew Litton conducted the Minnesota Orchestra in "Who Cares?" pairing it with a classic dance score, Aaron Copland's "Appalachian Spring" in a new version for symphony orchestra. (There was a nice symmetry to this, given that Litton is now music director of the New York City Ballet.)

Balanchine created "Who Cares?" for an ensemble of 20 dancers, a number that would be hard to accommodate on the Orchestra Hall stage. Wisely, for the performance Friday night, Litton used just four dancers, all from the New York City Ballet, who did just the solo and duet numbers. The stage was extended out into the auditorium, covering the first two rows of seats.

The result was really quite wonderful, surely the highlight of the festival. Kay's canny orchestrations have a brassy Broadway pit-band pizazz and yet make full use of the orchestra. Litton served as both conductor and an especially nimble pianist, elaborating on the solos that Gershwin himself notated. The dances — delicate and buoyant, traditional ballet with hints of Broadway chorus line, tap and soft shoe — seemed to lift the songs into the air and let them float like clouds.

The skilled dancers were Sterling Hyltin, Ashly Isaacs, Megan LeCrone and Andrew Veyette.

In the first half, Litton presided over a gently lyrical, rhythmically precise account of "Appalachian Spring" in a version completed last year by David Newman based on work Copland himself began in the 1950s. This version gives us the complete ballet score rather than the pared-down suite for large orchestra that Copland fashioned in 1945.

The suite, which is the version most people know, remains the stronger work, at least in concert performance. The complete ballet, which runs about 15 minutes longer than the suite, has quite a few dull pages. Copland knew what he was doing when he took out a pair of scissors and began to cut.

Michael Anthony is a Twin Cities classical music critic.