Simplify the following text for a Grade 13 native English-speaking person.
Original: Salonen 's tenure with the orchestra first began with a residency at the 1992 Salzburg Festival in concert performances and as the pit orchestra in a production of the opera Saint FranÃ ois d'Assise by Olivier Messiaen ; it was the first time an American orchestra was given that opportunity .
Simplified: At the beginning of Salonen 's time with the orchestra they gave regular performances at the Salzburg Festival and they played for a production of the opera Saint-Fran Ã ois d'Assise by Olivier Messiaen .