Like a fading memory of times gone by,” Thomas Heuser said in an interview this week, “images seem to dissolve and break apart. A saxophone soloist creates the mood of a smoky cabaret theater interrupted by raucous dancing and the occasional sound of the city streets.”

Heuser could be describing George Gershwin’s energetic “American in Paris” or the muscular “Rhapsody in Blue,” but the music director of the San Juan Symphony is commenting on John Harbison’s “Foxtrot for Orchestra,” one of two outliers on the program this weekend.

“Gershwin and the Roaring Twenties” is the title of our regional orchestra’s upcoming twin concerts. On Saturday evening in Farmington’s Henderson Performance Hall, and Sunday afternoon in Durango’s Community Concert Hall at Fort Lewis College, the San Juan Symphony will surrender to jazz.

“Our program is designed to highlight three of Gershwin’s masterworks,” Heuser said, adding a medley from Gershwin’s only opera, “Porgy and Bess.”

“We’re framing Gershwin’s music in the context of the Roaring Twenties, a period in American history fraught with idealism, social change and stylistic evolution.”

The orchestra will open with an arrangement of songs from “Porgy and Bess,” the opera inspired by DuBose Heyward’s novel Porgy. It took eight years to bring what Gershwin preferred to call his folk opera to the stage. The arrangement you’ll hear comes from a colleague of Gershwin’s, Robert Russell Bennett. He orchestrated Gershwin’s two Broadway shows: “Girl Crazy” and “Of Thee I Sing.” And in 1962, long after Gershwin’s untimely death in 1937, Bennett created this particular medley. Among other familiar songs, you’ll hear “A Woman is a Sometime Thing,” “Summertime” and “Bess You is My Woman.”

Heuser has invited pianist Roberto Plano, a musical colleague, to be the soloist for “Rhapsody in Blue.” Plano has performed standard classical concerti throughout Europe and North America, particularly Lincoln Center in New York and Wigmore Hall in London. Italian born, he is currently professor of piano at Boston University.

“The Gershwin Rhapsody seems perfectly suited to Roberto’s lively personality, and I am happy to have the chance to work with him on such an iconic and well-known work,” Heuser said.

The first outlier on the program is A Symphonic Portrait of Irving Berlin. He published his first song in 1907and was famously active throughout the ’20s. The Symphonic Portrait was arranged by Henry Ades, who worked for Berlin in the 1930s. The arrangement includes “Alexander’s Ragtime Band “and “God Bless America.”

The other outlier is a contemporary work by American composer John Harbison, born one year after Gershwin’s death. His 1999 opera, “The Great Gatsby,” is based on the F. Scott Fitzgerald novel of the same name. Because of permission rights, the opera stalled several times. In the interim, Harbison wrote an orchestral foxtrot which eventually became the overture. Its eight minutes contain musical foreshadowing of the opera and echoes of Gershwin’s genius, for example, car horns.

Heuser will also conduct the joyous and jazzy “An American in Paris.” Composed in 1928, the work brims with nostalgia. That spring, Gershwin and his brother, Ira, had gone to Europe, and while in Paris, the work-in-progress blossomed.

“Our American friend,” Gershwin wrote about his hero’s musical journey, “after strolling into a café and having a couple of drinks, has succumbed to a spasm of homesickness.”

Gershwin went on to describe a blues section that eventually “returns to the vivacity and bubbling exuberance of the opening part, with its impressions of Paris.”

Judith Reynolds is an arts journalist and member of the American Theater Critics Association.