Edited sentence: Davis was originally scheduled to step down after the 2007-2008 season, but in October 2007, Davis and the PSO mutually agreed to terminate his contract early and for him not to conduct his scheduled concerts in the 2007-2008 season, because of increased demands on Davis' schedule..  The contracts of Tortelier and Janowski also expired in 2008.During this period, a new collective bargaining agreement was in effect, which gave the musicians increased authority over matters of running the orchestra such as the hiring of musicians and choice of repertoire.In 2005, the PSO formally began lacking a single music director.Janowski now holds the Otto Klemperer Guest Conductor Chair with the PSO.Starting in 2005, Sir Andrew Davis served as the PSO artistic advisor, with Yan Pascal Tortelier as principal guest conductor and Marek Janowski holding the "endowed guest conductor chair"