CHARLESTON, South Carolina (AP) ― The Spoleto Festival USA opens its 36th season Friday and among the planned performances is an opera by American composer Philip Glass to commemorate his 75th birthday and his long relationship with the internationally known arts festival.

The Charleston festival is staging the American premiere of “Kepler,’’ about the famed German astronomer Johannes Kepler. Only the score has previously been performed in this country.

“We had been talking about various different things and this seemed the most appropriate,’’ said festival General Director Nigel Redden, who first met the composer 40 years ago. “It’s the American stage premiere but it’s also the premiere of a new version and it’s in English. Philip, I think, was anxious to have it done in English to make it more accessible.’’

Glass has had a long relationship with Spoleto. Among other performances over the years, the first American production of his “Book of Longing,’’ based on the poetry of Leonard Cohen, was performed in 2007. A year earlier, a minimalist fanfare by Glass was performed at the opening ceremonies on a so-called car-illon. The car-illon consisted of a line of BMWs, each with a speaker on the roof and a license plate displaying the note it played.

“This festival was founded by a composer and we feel increasingly it’s desirable to have composers here,’’ Redden said.

The Spoleto Festival USA was founded here in 1977 by composer Gian Carlo Menotti as a companion to his Festival of Two Worlds in Spoleto, Italy. He left the Charleston festival in 1993 in a dispute over his successor and died five years ago at age 95, still estranged from the festival he started here.

The festival’s opening ceremonies are Friday and during the following two weeks there will be more than 140 shows by 60 groups and performing artists on stages across the city.

A second Spoleto opera is the American premiere of “The Phoenix Pavilion’’ by Guo Wenjing, a contemporary Chinese composer. It features an orchestra of four traditional Chinese instruments blended with Western instruments.