San Diego Symphony president Douglas Gerhart has resigned from that position, saying that his candidacy for the top job in Pittsburgh had become a distraction. The financially embattled Pittsburgh Symphony Orchestra isn’t returning phone calls on the subject, but it’s possible that Gerhart has already been hired. The San Diego prez first surfaced as a leading candidate for the PSO job two weeks ago, based on his record of service with orchestras attempting to navigate dire economic straits.