Michael “Mickey” Bookspan was 24 when he joined the Philadelphia Orchestra and he went on to perform under the baton of three successive music directors. Holder of the principal percussionist position, he died in September at age 73. The search is now on for a replacement for the coveted position, filling the shoes of “arguably the principal percussionist in the greatest orchestra percussion section there ever was.” First they’ll go through resumes (due this week), then there will be auditions in February. The final few candidates will likely be asked to play for a few weeks with the orchestra to test their fit with the section. They’re not doing much publicity to recruit candidates; they don’t need to. As one percussionist said “Jobs like this open up once every 10 to 15 years.”