The Pittsburgh Symphony is in a tricky situation. It’s running deficits again, ticket sales aren’t up to snuff, and the orchestra is in the unenviable position of trying to remain in the top world ranks following the departure of renowned music director Mariss Jansons. Oh, and the musicians, who took a big pay cut a few years back, are due an unheard-of 25% raise this fall, the result of a contract which pegs their salaries to orchestras in New York, Philadelphia, Chicago, and Cleveland. Still, subscriptions are up, and previous deficits have been wiped out by last-minute contributions, so no one’s panicking yet.